5.1. english i don’t know

The discussion in this section is based on the data and discussion in Bybee and Scheibman (Reference Bybee and Scheibman1999) and Scheibman (Reference Scheibman2000), studies based on a small conversational corpus. Originally conceived as an examination of the reduction of don’t, it quickly became apparent that don’t reduces the most only in certain contexts. These are not phonetic contexts, but rather lexical and grammatical contexts (preceded by I and followed by certain verbs), distinguished by their high frequency.

As suggested by Kaisse (Reference Kaisse1985, p. 57), the auxiliary don’t is subject to a number of regular phonological processes that occur in connected speech. She mentions in particular the nasalization of the vowel, deletion of the nasal consonant, and deletion of the final /t/. In the Bybee and Scheibman (Reference Bybee and Scheibman1999) data, these processes were so pervasive in all variants that it was difficult to distinguish the variants by these criteria. However, another regular phonological process which is considered to usually occur within words – the flapping of the initial /d/ – occurred in some variants. Since flapping does not usually occur at the beginning of lexical words, this might be considered part of the special reduction process. It is explainable as the result of the chunking of the pronoun with don’t. As shown in Table 1, the flapping does not occur with a lexical subject. Kaisse takes the reduction of the vowel of don’t to schwa to be the indicator of its special status – in her analysis the cliticization of don’t. ^{Footnote 2} We also find the vowel reduction to be a major indicator of special reduction, since ordinarily stressed vowels do not reduce. A further indicator of special reduction (not mentioned by Kaisse) is the deletion of the initial /d/ of don’t.

table 1. Variants of don’t by type of item preceding or type of construction (Bybee & Scheibman, Reference Bybee and Scheibman1999, p. 581)

Thus the four variants categorized in Table 1 represent the full form, the chunked form with regular flapping applied to it, the special forms with the schwa vowel, and the most reduced form, with the deletion of /d/. The variants identified, then, show a phonetically gradual development from full to most reduced form. Further evidence for the gradualness of the development is the fact that in listening to the variants in context, it is often difficult to distinguish clearly among these categories. Nasalization of the vowel in don’t is not indicated in the table because it was too difficult to discern whether or not the vowel was nasalized, both when the nasal consonant was present, and, for different reasons, when the phrase was highly reduced.

The most striking conclusion to be drawn from Table 1, however, is the strong association of reduction, especially the most extreme reduction, with the frequency of the context. The sign of greatest reduction – the presence of the schwa – was found only with the most frequent pronoun – I. The one case of reduction to schwa outside that context was in the phrase why don’t you + VERB when used as a suggestion or request. The phrase I don’t precedes a variety of verbs, but don’t only reduces to schwa before verbs of high frequency such as know, think, have, have to, want, like, mean, feel, and care. Some of these phrases, especially I don’t know, have developed special discourse pragmatic functions, but the reduction to schwa also occurs in high-frequency phrases such as I don’t have and I don’t want, which are fully compositional in their meaning and function, underscoring the importance of repetition to special reduction.

The English case, then, illustrates our major points: the phonetic reduction that occurs in these special cases includes the regular reduction processes present in the language: here we see the regular processes of flapping of /d/, vowel nasalization, and loss of final /t/ and /n/, and the further more extreme reduction of the vowel /o/ to schwa, deletion of the flap, and loss of vowel nasalization. The more extreme reductions are continuations of processes already begun in the regular reduction observable elsewhere in the language: reduction of a full vowel to schwa is an ongoing process that affects all unstressed vowels; flapping is the reduction of the duration of the alveolar contact and if continued in this same direction, leads to deletion; vowel nasalization and weakening of a nasal consonant if continued in a reduction context leads to loss of nasalization. All of these processes depend upon changes in the stress pattern of the phrase. The full phrase I don’t + VERB has three prominent syllables, one for each unit. But in the reduced phrase, don’t loses its prominence, leaving two prominent syllables in the phrase and leading to the reduction of don’t. We will see similar trends in the other two cases we discuss.

5.2. brazilian portuguese: the reduction of deixa eu

One of the key characteristics of Portuguese that distinguishes it from closely related Spanish is the large number of unstressed vowel reduction phenomena that have continuously affected its phonology. Historically, the full oral vowel inventory [i e ɛ a ɔ o u] as found in stressed syllables was reduced to five vowels [i e a o u] in non-final unstressed position and in unstressed final position to a three-vowel system [ɪ ə ʊ] in most dialects of Brazilian Portuguese (Câmara Jr, Reference Câmara1972, Teyssier, Reference Teyssier1984; Cristófaro-Silva, Reference Cristófaro-Silva1999). While stressed oral vowels have maintained a high degree of stability since the early days of the language, unstressed vowels have frequently undergone further reductions in Brazilian Portuguese. These include the raising of non-final [e a o] to [ɪ ə ʊ] (Callou, Leite, & Moraes, Reference Callou, Leite and Moraes2002; Ribeiro, Reference Ribeiro2007), extreme reduction or deletion of unstressed high oral vowels [ɪ ʊ] (cf. Bisol & Hora, Reference Bisol and Hora1993; Amaral, Reference Amaral, Bisol and Collischonn2009; Napoleão de Souza, Reference Napoleão de Souza2014), and deletion of unstressed final [ə] when followed by a stressed vowel across words (Bisol, Reference Bisol, Bisol and Collischonn2002). It is noteworthy that raised vowels are also subject to deletion (Soares & Barbosa, Reference Soares and Barbosa2010). ^{Footnote 3}

The reduction of the phrase deixa eu [ˈdeɪ.ʃə ˈeʊ] ‘let me’, lit. ‘let I’ to a single syllable pronounced [tʃo] in contemporary Brazilian Portuguese is another example of how special reduction affects very frequent phrases. The sequence deixa eu + verb is a construction used as a discourse marker (e.g., deixa eu ver ‘let me see/think’) or as a means to express polite suggestions, as in deixa eu te ajudar ‘allow me to help you’. It can occur followed by any verb in the infinitive or by a second person oblique pronoun when the speaker is addressing the hearer directly, as in deixa eu te ajudar.

The phrase deixa eu is pervasive in conversational corpora and almost always appears in reduced form. An investigation of a corpus of spoken contemporary spontaneous Brazilian Portuguese (Raso & Mello, Reference Raso and Mello2012) yielded sixty-one occurrences of the construction deixa eu + verb, none of which corresponded to the historically full form [ˈdeɪ.ʃə ˈeʊ]. In fact, even the least reduced form found in the corpus, [deˈʃo], shows some characteristics of special reduction, given that the verb and the pronoun occur as a single chunk and the prominence of the first syllable in the word deixa is totally lost. Table 2 distinguishes four variants, the most common of which is [tʃo], occurring 72% of the time. The fuller form [deˈʃo] only occurred in 10% of tokens and two more reduced forms, [ʃo] and [ʃ], also occurred.

table 2. Variants of deixa eu by degree of reduction

The variants observed suggest a phonetically gradual development from full to the most extremely reduced form. The present data and previous literature allow for the hypothesis that this special reduction followed a specific path in which successive reductions affected the phrase to yield each of the variants found and some others we did not observe. The possible special reduction cline for deixa eu is shown below, with bolded characters representing the reductions present in our data:

1. (1) [ˈdeɪ.ʃə ˈeʊ] > [ˈde.ʃə ˈeʊ] > [de.ˈʃeʊ] > [de.ˈʃo] > [tʃo] > [ʃo] > [ʃ].

The first reduced form above, [ˈde.ʃə ˈeʊ], although unattested in the present data, shows frequently occurring reduction patterns in that [eɪ] is monophthongized to [e] before [ʃ] (cf. Almeida, Reference Almeida2008; Brescancini, Reference Brescancini, Bisol and Collischonn2009). The remaining reductions are special in the sense that there is chunking of the two elements in the original phrase and a subsequent loss of stress in the word deixa in each of these cases. In [de.ˈʃo], the least reduced form in our data, the consequences of chunking in the loss of the unstressed final vowel in deixa are already apparent, but more importantly, the maintenance of the stress on the syllable containing eu seems to condition the loss of stress on the first syllable. To arrive at the variants that are attested, the [eʊ] diphthong becomes a monophthong. The most common variant in the corpus, [tʃo], illustrates a further reduction, in which the now unstressed vowel [e] of the first syllable is deleted and there is a voicing assimilation in [dʃ], which yields [tʃ]. Loss of [e] is noteworthy given that high vowels alone tend to be deleted in unstressed position in Brazilian Portuguese (see discussion in the beginning of this section). In [ʃo] we observe the loss of all segmental information in the erstwhile stressed syllable of deixa plus a lenition of the affricate [tʃ] to [ʃ]. Last, the five occurrences of [ʃ] show an extreme case of special reduction in that the only remnant of the segmental (and indeed suprasegmental) information in the phrase [ˈdeɪ.ʃə ˈeʊ] is the palatal fricative. It is relevant that all of the tokens analyzed in this corpus exhibit a loss of prominence that was present in the original word deixa. The loss of prominence makes way for reduction phenomena to occur. As we will show in Section 6, the loss of prominence is due to the chunking of the sequence as a unit and its high frequency.

A closer examination of the context of each of the four reduced variants in the corpus revealed that almost two-thirds (64%) of the occurrences of the extremely reduced forms [ʃo] and [ʃ] were followed by the verb ver in the phrase deixa eu ver ‘let me see/think’. In fact, the phrase deixa eu ver alone represented 79% of the total tokens of deixa eu in the spoken corpus investigated. The second most frequent word, dar ‘give’, only had three tokens, followed by te (2s.obj), which had only two. The eight remaining occurrences of the phrase each combined with a different verb. These results suggest that the greatest variation – including the highest number of tokens of extreme reduction – occurs in the context in which the phrase is used most frequently, just as in the case of English don’t. Table 3 shows the variation in the reduction type according to frequency.

table 3. Reduction type of deixa eu according to token frequency

In order to investigate the specific role of frequency in the special reduction of deixa eu ver, an analysis of a much larger corpus of contemporary Brazilian Portuguese, the Corpus Brasileiro, was undertaken. In that corpus, the collocation with ver alone represents 39% out of the 383 occurrences (0.3 per million) of the construction deixa eu + verb. The second most common collocation of deixa eu contains an oblique pronoun in the first slot, as in deixa eu te falar ‘let me tell you’ and had 68 tokens (18%) in total. The third most frequent collocation, with the verb fazer ‘do/make’, occurred in only 4% of the tokens. Table 4 contains the results of the frequency analysis.

table 4. Frequency of different words occurring in the verb slot of the construction deixa eu in the Brasileiro corpus of contemporary Brazilian Portuguese (one billion words)

Our examination of the variants of deixa eu, then, shows that the greatest reduction occurs in the most frequent context, just as we found in the case of the reduction of I don’t. We also found that a major factor in the extreme reduction of this phrase was the loss of stress or prominence on the first syllable, which, we argue below, is the result of the chunking of this phrase. Given the starting point of the phrase and the existing variants, we also have reason to believe that all the reductive changes that occurred were phonetically gradual.

5.3. caleño spanish o sea

The Spanish discourse marker, o sea ‘that is’ or literally ‘or be+subj+3s’, has been the focus of numerous studies in pragmatics (cf. Schwenter, Reference Schwenter1996; Galán Rodríguez, Reference Galán Rodríguez1998; Félix-Brasdefer, Reference Félix-Brasdefer, Face and Klee2006), which have been primarily aimed at classifying the pragmatic uses of the phrase in discourse, and how it fits into earlier typologies of discourse markers (Schiffrin, Reference Schiffrin1987; Fraser, Reference Fraser1999). Relying primarily on data from Alicante, Spain, Schwenter (Reference Schwenter1996) notes that the uses of o sea have extended beyond the simple subjunctive form of the verb ser ‘to be’ to encompass meanings that can be grouped into two broad classes within the category of discourse markers: connectives and epistemics. He defines connective uses as being those that “guide hearers to the correct semantic interpretation between propositions”, while “epistemic uses mark speakers’ degree of commitment to what they say, increasing the modal content of their utterances” (p. 855). An example of each follows:

1. (2) Connective:

   Nos sentábamos siempre en el mismo lugar, o sea como en la segunda, como en el segundo bloque de sillas que hay en la catedral.

   ‘We always sat in the same place, that is like in the second, like in the second block of seats that are there in the cathedral.’

2. (3) Epistemic:

   ¿Qué hacemos los universitarios? Pues que depende o sea yo creo los estudiantes universitarios nos dividimos como en dos lados.

   ‘What do we students do? Well that depends I mean I think that we university students are divided into two groups.’

In terms of phonetic variation, o sea has received very little attention beyond impressionistic analyses. Schwenter notes that it occurs in a prosodically independent position, often separated from the surrounding context by pauses, intonation breaks, or both, and is subject to reduction: “Although often reduced from its full phonological form /osea/ to [osa] or [sa] and unstressed, it may also be stressed with an elongated final vowel [osea:] when in final position” (1996, p. 858); Félix-Brasdefer (Reference Félix-Brasdefer, Face and Klee2006) makes similar observations with respect to the reduction in present-day Mexican Spanish.

Here we examine the distributional data and the gradient phonetic properties of both the o sea discourse marker (DM) and its subjunctive (SUBJ) predecessor in sociolinguistic interviews produced by fourteen people (11 females, 3 males) from Cali, Colombia. In terms of overall distribution frequency, we report a 28:1 ratio in favor of the DM over the SUBJ uses, which is in stark contrast to distributional data retrieved from publically available corpora such as El Corpus del Español, a corpus consisting predominately of written texts and formal registers. In that corpus the SUBJ accounts for 68,633 (91%) vs. the DM with 6,796 (9%) overall; the count for the twentieth century is SUBJ 6,699 (53%) vs. DM 5,870 (47%), and 2,859 (35%) vs. 5,403 (65%) in the twentieth-century oral genre only. We suggest that frequency counts based on dialect-specific, spontaneous, informal speech styles (when available) are more likely to capture patterns of phonetic reduction.

To arrive at a more objective analysis of the gradient reduction of o sea, an acoustic analysis was undertaken using 174 tokens of the DM and 11 tokens of SUBJ. This gradient analysis not only corroborates the impressionistic intuitions provided by Schwenter and Félix Brasdefer, but also provides more specific details regarding the types of reduction present, which include both temporal and gestural dimensions. Some of these are represented in Figure 1. Overall, the DM is produced with shorter mean durations than the SUBJ (195ms vs. 256ms) as shown in the first boxplot, with a range between the DM and SUBJ of 51ms; the median durations are even more notable: DM 175ms and SUBJ 262ms. These measurements do not include the /o/ gesture, but even when that is included, the DM is still significantly shorter (–35ms). In terms of individual gestures, they examine the /s/ and /ea/ sequences separately.

Fig. 1. Temporal and gestural reduction in discourse marker o sea vs. subjunctive sea.

In the DM, the sibilant /s/ is realized with a significantly shorter duration (boxplot 2), a lower center of gravity (boxplot 3), and tends to be produced with more voicing (boxplot 4) when compared to the /s/ in the SUBJ. The center of gravity is based on one of the spectral moments identified in Forrest, Weismer, Milenkovic, & Dougall (Reference Forrest, Weismer, Milenkovic and Dougall1988), which measures the central tendency (i.e., the mean) of the spectrum and is a weighted average of the frequency peaks over a specified interval. Lowering of the centroid is interpreted as a weakening tendency in terms of a lowered tongue gesture (cf. Erker, Reference Erker2010; File-Muriel & Brown, Reference File-Muriel and Brown2010, Reference File-Muriel and Brown2011). The weakening of /s/ in syllable-initial position is a known tendency in Caleño Spanish (Brown & Brown, Reference Brown, Brown, File-Muriel and Orozco2012), as well as in other varieties (Brown & Torres Cacoullos, Reference Brown, Torres Cacoullos and Nunez-Cedeno2003). The important point here is that s-reduction is more advanced in the high-frequency DM than in the infrequent SUBJ, which lends support to our hypotheses.

Regarding the articulation of the vocalic sequence /ea/, interestingly, there does not appear to be a significant difference with regard to duration between the SUBJ use and DM use, likely due to the fact that the DM is often elongated in utterance-final position. However, upon considering the formant trajectories and, specifically, the degree of acoustic differentiation between the early [e]-like part, and the later [a]-like part in terms of a Euclidean distance measure of two sets of F1 and F2 measurements (Figure 1, boxplot 5), the DM tends towards a monophthongal articulation (i.e., [a]), while the SUBJ appears to be more diphthongal or hiatus-like (i.e., [ea]). The Euclidean Distance is a metric distance from point A to point B in a Cartesian system (derived from the Pythagorean Theorem) and is represented as follows: Distance ← sqrt((F1 = x1–x2)^2+(F2 = y1–y2)^2). Point 1 is taken 25ms following the offset of frication from [s], to compensate for formant transitions, and point 2 is taken at the maximum F1, which defines the [a]-gesture. Thus, monophthongal articulations, such as that shown in Figure 2, have lower distance measures than more diphthongal and hiatus-like articulations, such as that shown in Figure 3.

Fig. 2. Monophthongal articulation of discourse marker o sea.

Fig. 3. Hiatus-like articulation of subjunctive sea.

It should be noted that the reduction of vowels in hiatus (e.g., /e.a/) to diphthongal realizations [ja] is a general tendency that has been observed in the Romance languages to different degrees depending on the language (cf. Chitoran & Hualde, Reference Chitoran and Hualde2007), and specifically in Latin American Spanish (Alba, Reference Alba2008; Garrido, Reference Garrido2013). Alba notes that “hiatus is commonly resolved in some way in speech. Possible resolutions include deletion of one vowel (e.g. /a/+/e/ > [e]), creation of a diphthong (e.g. /a/+/e/>[ai̯]), coalescence of the two vowels into a different one (e.g. /a/+/e/>[ɛ]) and insertion of a consonant (e.g. /a/+/o/>[aɣo]. Although hiatus is most often resolved in one of these ways, it may also simply be maintained” (p. 251).

In short, this analysis shows that the DM o sea is characterized by clear patterns of gestural reduction when compared to the SUBJ sea, from which it evolved. The highly frequent DM is not only shorter in duration overall, but shows patterns of reduction in terms of s-realization (i.e., shorter duration, lower center of gravity, and more voicing) and the monophthongization of the vocalic sequence /ea/. It was pointed out that the gestural reduction observed in o sea are patterns seen elsewhere in the language, but o sea is much farther along than its SUBJ predecessor.

6.1. phonetic effects of chunking

The case studies from the three languages support Hypotheses 1 and 2, i.e., that special reduction is determined by phonetic trends already present in the language which are accelerated in high-frequency phrases, and that special reduction is phonetically gradual. In an exemplar model, all words and phrases are subject to certain phonetic biases and the resulting phonetic tokens affect the stored exemplars, often moving these phonetic processes along. Two factors make special reduction special: one is high frequency, which allows the accumulated phonetic biases to create a wider range of variation, including extremely reduced variants, and the second is the chunking of a sequence of words or morphemes into a single production unit. ^{Footnote 4} As noted above, high frequency does not cause reduction, but it facilitates it because high-frequency items are more often exposed to the production biases that cause reduction.

Chunking plays a role in the three examples described in the previous section. In fact, chunking would seem to be the first step in the process of special reduction. Barth-Weingarten and Couper-Kuhlen (Reference Barth-Weingarten, Couper-Kuhlen, Auer and Pfänder2011) argue that the production of a sequence as a single prosodic unit and the implementation of the regular phonetic processes that occur in such units is an important first stage in the creation of a new morphosyntactic whole, be it a discourse marker or a new construction. Our examples show that subsequent repetitions push these regular processes beyond their usual outcomes.

Our examples also show chunks within chunks. The phonetic fusion found in I don’t seems to be a good indicator of chunking. This chunk in turn occurs in larger chunks such as I don’t know, I don’t think, and I don’t mean, as well as other combinations. Similarly, deixa eu becomes a single processing unit, but it also occurs in the chunk deixa eu ver ‘let me see/think’, which takes on an expanded interactional function. But the reduced form of deixa eu also occurs with some other frequent verbs, so it is a chunk within a larger chunk. The Spanish discourse marker o sea is a simpler composition, consisting of one unitary chunk.

The examples also show, in accordance with Hypothesis 3, that one outcome of the frequent repetition of chunks is the loss of some of the prominence on what were earlier stressed syllables. Thus I don’t know in its fullest and original form would have the same stress pattern as I don’t inhale – that is, full prominence on don’t and the verb. The reduced forms are characterized by less prominence on don’t and a declining prominence on I as well. As the prominence we designate as ‘stress’ is manifested as increased duration and amplitude and higher pitch, the diminution of these properties is in itself reduction. Thus we are less inclined to describe these changes as a loss of stress and more inclined to think of them as the normal outcome of increased reduction. Thus the whole unit I don’t reduces and only the verb (in this case know) retains lexical stress.

Brazilian deixa eu also started with stress on the first syllable of deixa and a stress on eu. As we explained above, the fusion of the final (unstressed) vowel of deixa with the pronoun eu yielded a stressed syllable in [de.ˈʃeʊ]. The relative prominence of [de] is much less than the following syllable, and it is the one that further reduces.

In Spanish, it is common for two vowels in sequence (in hiatus) to undergo change, starting with diphthongization and continuing to a monophthongal realization. This is precisely what is occurring in the o sea DM, but not in the infrequent SUBJ, which appears to be maintaining the two original vowels. It should be noted that, in the original construction, tonic stress is said to fall on the first vowel in the sequence (e.g., /ˈse.a/). This is precisely the vowel gesture that appears to be undergoing reduction (e.g., [ˈsa]), in line with our Hypothesis 4. A further reduction affects the vowel /o/, which in the majority of cases (61%) is not realized.

We propose that the chunking of the words into a single unit, and the continued reduction they undergo, is responsible for the loss of syllables as well as the reduction of prominence on syllables that were earlier stressed.

6.2. pragmatic and semantic factors in chunking and special reduction

Since chunking and fusion can occur in the absence of semantic/pragmatic change, and indeed, chunking does not require extremely high frequency, we conjecture that it occurs independently of functional change and in fact precedes any change in meaning or function. Examples of chunked sequences undergoing special reduction in the absence of functional change are the fusion of prepositions with articles (listed above), the contraction of English auxiliaries with preceding pronouns (I’ll, I’ve, he’s, he’d, etc.) and the contraction of English not with a preceding auxiliary (can’t, don’t, couldn’t, wouldn’t, etc.). Thus, chunking may occur rather mechanistically, with the cognitive system responding to the frequency of sequences in experience (Saffran, Aslin, & Newport, Reference Saffran, Aslin and Newport1996). However, there are two ways that functional factors also come into play in chunking and thus in special reduction.

First, it is commonly noted that chunked sequences, especially those of high frequency, take on new functions in context. Most of the examples we have cited here show some functional change: I don’t know can be used as a discourse marker (Scheibman, Reference Scheibman2000), as can o sea (Schwenter, Reference Schwenter1996). Deixa eu ver has interactional functions as well. Special reduction is characteristic of grammaticalization, which also includes functional change. However, detailed studies of the relation between reduction and function do not show a one-to-one correspondence in the variable stage. Bybee and Scheibman (Reference Bybee and Scheibman1999) find in the corpus used that the reduced vowel in I don’t know occurred in both the compositional meaning and in the discourse function, and, while the full vowel favored the compositional meaning, it also occurred once in the discourse function. Thus new functions do not cause special reduction, but rather coincide with it. However, new functions can play a role in that they usually mean an increase in the frequency of use, which helps to propel reduction forward. The new functions also reinforce the unitary nature of the expression, leading to a loss of compositionality of meaning. As the component parts within the expression are less likely to be activated when the expression is used, nothing prevents further phonetic reduction.

Second, a much more subtle role of function can be seen early in the development of chunks, as pointed out by Barth-Weingarten and Couper-Kuhlen (Reference Barth-Weingarten, Couper-Kuhlen, Auer and Pfänder2011). They argue that the development of a chunk requires that it occur in a single turn-constructional unit in conversation, that it implement a single action by the speaker in the conversation, and that it have phonetic and prosodic integration. The construction they discuss, VP₁ and VP₂, can be used in various ways. It can depict two separate actions, as in think that over and find out, or one single action, as in come and deliver, go ahead and take it, or cases that are intermediate. Their finding is that, even with novel combinations, the phonetic and prosodic integration corresponds to the extent to which a single action is depicted, as in the following example, about driving on a road after it has been paved, in which the two VPs describe a single event:

1. (4) It’s so delightful to come down the road and not be followed by a cloud of dust.

The integration of the two VPs prosodically, and the reduction of and in a novel combination, suggest (as the authors note) the development of a new construction. At the same time, as we would predict, certain more frequent combinations have become constructions, called hendiadic constructions (Hopper, Reference Hopper, Bybee and Noonan2001). Examples are try and … , go ahead and … , come and … , go and … .

Thus the study of chunking to date has identified a number of factors that contribute to the process: the sequence should be repeated in experience, produced as a prosodic and phonetic unit, it should occur within a single turn-constructional unit and implement a single function within the discourse. These factors set up the conditions under which regular phonetic processes occur. With repeated use and changes in the exemplar representation for the phonetic shape, as well as changes in the set of semantic and pragmatic exemplars, special reduction begins to emerge.

8.1. loss of initial consonants in english

In some of the more extreme reductions of a phrase like I don’t know, one observes not only the expected reduction and subsequent deletion of vowels that have lost stress, but also the deletion of all consonantal segments in extreme cases like the variant [ə̃]. Although deletion of final [d] and [t] is a common process in American English (Bybee, Reference Bybee, Barlow and Kemmer2000b), initial and intervocalic consonant deletion is not found so often. However, the in the contexts in which /t/ and /d/ become flaps, they are often so short as to be barely audible, suggesting that they might eventually undergo a deletion process as does the /d/ in I don’t know.

High-frequency phrases can create the conditions in which consonants may undergo reduction. For instance, under certain conditions, the glottal fricative [h] is lost in the pronouns him and her, as in Give him the cookie, in which the words give and him form a unit that is pronounced [ˈgɪvɨm]. We argue that this is related to a much earlier change in which the Old English third person neuter pronoun hit lost its initial glottal fricative to give rise to it. Another special reduction involving the loss of an initial consonant is the reduced rendering of I’m gonna, which occurs only in the intention/future expression. Here, the [g] in gonna might be completely deleted yielding [ˈaɪmə̃ɾ̃ə̃], [ˈaɪmnə] or even [ˈaɪmə].

The special reduction of don’t and others like her/him and gonna point to the fact that at least some English consonants may be prone to deletion when they occur in the appropriate context. If the initial segments in these words are consistently lost when produced intervocalically, this sound change trend might at some point apply more generally in the language.

8.2. vowel deletions giving rise to consonant clusters in portuguese

When chunking of the elements in the phrase deixa eu causes the historically stressed vowel in [ˈdeɪ.ʃə] to delete, the result is the unexpected consonant cluster [tʃ]. This seems to go against a commonly reported trend in Brazilian Portuguese to eliminate consonant clusters through epenthesis (Câmara, Reference Câmara1972), but in fact the creation of new clusters has a long history of occurrence in the language.

As early as the Late Latin period, word-medial unstressed vowels were lost, giving rise to consonant clusters in early Romance. The loss of those vowels in Latin words like vetulu, tegula, and oculu ‘old’, ‘tile’, and ‘eye’ created different clusters like /tl/, /gl/, and /kl/. Although most of these clusters were subsequently changed to a single segment [ʎ] by the Early Portuguese period (around the twelfth century), the trend has nonetheless persisted well into the present. As mentioned above, the deletion of unstressed vowels which causes consonant clusters to emerge has been reported both in word-medial (cf. Bisol, Reference Bisol2000; Amaral, Reference Amaral, Bisol and Brescancini2002) and word-initial (Amaral, Reference Amaral, Bisol and Collischonn2009; Napoleão de Souza, Reference Napoleão de Souza2014) positions in more recent years. In the aforementioned studies, it is mostly the vowels [i u] that are deleted, but word-medial unstressed [ə ɨ] have also been reported to reduce to zero.

The phonetic trend in which unstressed vowels become shorter and prone to deletion stems from the fact that lexical stress has become increasingly correlated with longer vowel duration in Portuguese (to a much greater extent than in Spanish). Though the consequences of such a reduction may seem extreme in cases like deixa eu [ˈdeɪ.ʃə ˈeʊ] becoming [tʃo], the phonetic patterns that motivate it have been operational in the language for quite a long time. The special reduction data in this paper suggest that all unstressed vowels, independent of height, may be prone to deletion in the future. Moreover, the present and previous studies seem to indicate that the consonants adjacent to the deleted vowel may be preserved in some form. The present changes might thus indicate that new consonant clusters will once again emerge in Portuguese. In the case of [tʃ] in [tʃo], the most frequent reduced variant of deixa eu, the results of the reduction might be viewed as a precursor of the full phonologization of the consonant (for further evidence, see Cristófaro-Silva, Reference Cristófaro-Silva2003).

8.3. vowel and consonant deletions in spanish

In the history of Spanish, phonological processes that lead to consonant lenition seem to be responsible for some of the major changes that took place in the language. For instance, Spanish lenited early Romance [ʎ] resulting from the consonant clusters /tl/, /gl,/ and /kl/ mentioned above to [j] or [χ], depending on the context. Also, there is evidence that now regular lenition of intervocalic /b d g/ to [β ð ɣ] and their ongoing deletion in many present-day dialects may have started in the Old Spanish period. By the fourteenth century, the early Old Spanish [d] in second person plural marking of present tense verbs -des was variably deleted, as in [kanˈtades] > [kanˈtaes] ‘you (pl.) sing’ (Penny, Reference Penny1991, p. 138). This change subsequently progressed to other verb tenses until it reached the entire verb paradigm, suggesting that what was once a special reduction became a regular change that affected all second person plural forms.

The vowel assimilation we report in [oˈsea] becoming [oˈsa] differs from the more regularly observed changes in Spanish in that it affects vowels instead of consonants. When one looks into the history of the language, however, it is possible to identify similar instances of two vowels reducing to one given the right phonetic context and frequency of use. The contraction of prepositions and articles is one such example, as in a + el [a el] to al [al] ‘to the’ or de + el to del ‘from the’. The reduction of a hiatus in a highly frequent construction may indicate that similar sequences could get reduced in the future. As consonants lenite and face deletion in many contemporary varieties of Spanish, as in lado [laðo] > [lao] ‘side’, the number of appropriate contexts for such a reduction to occur may abound in the future.

At first glance, special reduction might seem to operate in ways that are incompatible with the phonology of the language it affects. Indeed, some of the more extreme outcomes of special reduction might differ significantly from more regular phonological patterns one finds in a language. However, special reduction follows phonetic trends that have been present in the language, often for hundreds of years. The combination of right phonetic context – which is specific to each language – with a very high frequency of use may accelerate the process, sometimes creating unexpected outcomes. Nonetheless, as the study of historical facts discussed in this section illustrates, special reduction might presage regular sound change phenomena occurring at a later date.