0 Introduction
It is well known that in some cases English stress performs a grammatical function in encoding the syntactic categories of the words concerned. For instance, this phenomenon can be observed with disyllabic words in -ate, with create and negate being backstressed ([01]) because they are verbs, while climate and senate are forestressed ([10]) because they are nouns. The difference holds for those which belong to several syntactic categories, as with filˈtrate and dicˈtate (verbs) vs ˈfiltrate and ˈdictate (nouns). The same phenomenon affects words with separable prefixes, like ˌupˈdate and ˌoverˈdose (verbs) vs ˈupdate and ˈoverdose (nouns).
One class of words is especially affected by this type of stress alternation, namely disyllabic noun–verb pairs starting with an etymological, inseparable Latin prefix, such as obˈject and reˈcord (verbs) vs ˈobject and ˈrecord (nouns). Interestingly, this alternation is far from being a general rule, since two other tendencies exist: pairs where both members are backstressed (conˈcern, deˈfeat) and pairs where both members are forestressed (ˈcomment, ˈconvoy). Using their own corpus, Abasq et al. (2014) indicate that the isotonic CONˈCERN type represents 59% of all pairs, the isotonic ˈCOMMENT type 13%, while the alternating OBJECT type fits in-between with 28%.
This broad description obviously raises the problem of understanding why this threefold distribution exists, specifically the alternating type. Yet it conceals at least two even more intricate problems. The first – and more immediate – is the existence of synchronic stress variation, as can be seen with dispute (noun) and increase (noun or verb), which may be stressed on either syllable. The second problem is diachronic variation. For instance, perfect (verb), now backstressed, used to be forestressed. Conversely, convoy (verb) changed from [01] to [10]. Of course, both problems are linked. For example, while discount (verb), alloy (noun) and research (noun and verb) used to be only backstressed, they may now be stressed on either syllable.
1 Description in the literature
This change in stress placement, which dates back to at least the sixteenth century (Minkova 2014: 311), has often been described, but most studies refer to Sherman (1975) as being the first to examine the phenomenon in detail.