1.在“Our English teacher does what she can (to help) us improve our English ''中what she can 省略了do 這個(gè)動(dòng)詞,what引導(dǎo)的是一個(gè)賓語(yǔ)從句,而 (to help) us improve our English 為目的狀語(yǔ)從句.這個(gè)句子寫(xiě)完整就應(yīng)該為：Our English teacher does what she can do (to help) us improve our English.
2.動(dòng)詞后什么時(shí)候跟to ,什么時(shí)候不跟to,需要平時(shí)的積累,如stop doing sth不做某事. ; stop to do sth.停下來(lái)做某事；remember doing sth.記得曾做過(guò)的事；remember to do sth.記得要做某事；還有一些動(dòng)詞只能跟doing,如finish doing sth.practise doingsth.等等; 有些只能跟to do .如：want to do sth.; hope to do sth.等等.
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