what____you____(buy) yesterday ?这里如何填空？

来源：百度知道 编辑：UC知道 时间：2024/06/06 09:27:51
what____you____(buy) yesterday ? 我见有人填为what did you buy yesterday ? 这个句子是一般过去时，为啥后面的buy不改为bought？ 还是只是他回答错了？这个句子正确的应该为what did you bought yesterday?
为啥是did buy呢？ 没弄明白…… 可以举几个例子吗?

what__did__you__buy__(buy) yesterday ?
did已经体现了过去时，bought应改为原型buy

did是助动词，本身就有过去事态，后面只能跟原形！

what did you buy yesterday ? did已经表现了过去时，所以bought应改为原型buy

did buy