“动词原形”用英语怎么表达？

原形： basic form 如 write
不定式：infinitive 如 to write
过去式：past tense 或 preterite 如 wrote
过去分词：past participle 如 written
现在分词：present participle 如 writing

original form of a verb

bare infinitive
语法书上的

base form of a verb

verb