Basic issues

We have said that a theoretical model if it is to be considered adequate must be capable both of describing and accounting for the observed phenomena. Which phenomena are in fact selected for attention by the linguist at any particular period will depend upon prevailing attitudes towards the subject and towards scientific investigation in general. Two main issues dominated the early course of historical linguistics, namely synchronic irregularity within individual languages and the nature of the resemblances existing between related languages. As we shall see, the two questions are in fact intimately connected.

Synchronic irregularity

One problem which obviously requires explanation in a language is its so-called irregular forms, and it could even be said that the more irregular the form the greater the need for it to be explained. Regular past tense forms like grabbed /græbd/ or hoped /houpt/ may perhaps be taken for granted, but why should to keep have a past tense kept /kept/ or to bleed /bli:d/ a past tense bled /bled/? We describe these last two forms as irregular because they do not follow the productive rule for forming the past tense in English which, depending upon the nature of the final segment of the verbal base, suffixes one of the alternants /-d, -t, -id/. We say that this rule is ‘productive’ because if native speakers of English are asked to form the past tense of some real or hypothetical English verb that they have never heard before they will without hesitation produce a form in compliance with it.