Category:Quirk Irregular verbs

Quirk 1985 lists "250 or so irregular English verbs". These are classified into seven classes. These are identified by reference to three characteristics.

• The first is the use of suffixes in the past forms. These can be
  • the standard -ed suffix of the regular verb, with
    • the unvoiced variant -t, as in 'learnt';
  • and the nasal variant -n, as in 'shaken' and 'torn'.
• The second main characteristic by which irregular verbs can be classified is V-ed identity in the two past forms: whether the past tense has the same form as the past participle.
• The third is vowel identity: whether the vowel in the present tense is the same as that in the past tenses.

The following table is after Quirk (1985), p. 104. In it, the symbol '+' in any row means that the relevant characteristic (identified in the column heading) is present in that class; the symbol'-' indicates its absence. In class 2, either of two suffixes may be used with the past participle - as shown by the use of '+/-'.

It may be of some interest that Quirk 1973, an earlier book by Quirk's team, uses a slightly different labelling.