When his mother asked him to wash his hands

问题描述:

When his mother asked him to wash his hands
为什么是“ to wash”而不是 washed?

ask sb.to do sth.是固定的用法这个句子是过去时,如果ask sb. to do sth.是固定的用法的话,那就应该是“to washed”呀?不定式后面没有时态变化,要是变就变前面的ask,将ask变成asked