principal parts
noun /ˌprɪnsəpl ˈpɑːts/
/ˌprɪnsəpl ˈpɑːrts/
[plural] (grammar- the forms of a verb from which all the other forms can be made. In English these are the infinitive (for example swim), the past tense (swam) and the past participle (swum).
Topics Languagec2(动词)主要部分, 主要形式 (英语中有动词的不定式、过去时和过去分词)