Definition of principal parts in US English:

principal parts

plural noun

  • The forms of a verb from which all other inflected forms can be deduced, for example swim, swam, swum.

    • ‘The stronger the principal parts of speech, the stronger the writing,’ ASNE judge Cunningham said.’
    • ‘Better grammars (like Smyth) will give you that sort of information in their full discussion of the morphology of verbs; they will also give you lists of principal parts of most irregular verbs.’
    • ‘To sum up, to use any verb fully, you must know two things: (1) all the principal parts of the verb, and (2) the rules governing the conjugation of English verbs.’
    • ‘Asked to recite the principal parts of the verb ‘to eat’, the irrepressible Hyman Kaplan suggested the following: ‘eat, ate, full.’’


principal parts

/ˈprɪnsəpəl pɑrts/