didn't 的原形是do not , do為助動(dòng)詞,助動(dòng)詞后面都是跟動(dòng)詞原形.
do homework是做作業(yè)的意思.
He didn't do his homework yesterday.
他昨天沒(méi)有做作業(yè).

那把didn't 拆了吧
He did not do his homework yesterday.
do的過(guò)去式是did,因?yàn)閐o作為助動(dòng)詞時(shí),后面加動(dòng)詞原形,所以跟在did后面的動(dòng)詞也是用原形.再問(wèn)一下。I went to your home，but you weren‘t in you不是單數(shù)嗎。為什么不用wasn’t?還是有別的原因。求解。、最好快點(diǎn)。或者能留個(gè)Q不--。偶加分。you 后面一定是跟are，不論是代表“你”或“你們”意思，不能跟is。沒(méi)有you is 的用法。這是英語(yǔ)固定的搭配。