",and"的用法

jupiter410

我看到prep1 97对 WHILE+DOING的解释，上面说：

while引导从句时,如主从句的主语一致,且从句谓语又含有be,则从句主语和be可省略。while后可直接跟现在分词、名词、形容词或介词短语。

请问到底是，主句主语一致时，while后就可以+doing

还是要主句主语一致，且位于动词为BE时呢？

谢谢~

terry_run

good questions.

In my opinion, as long as the subjects are same, "while doing" is acceptable.  Of course, the Verb needs to have -ing form, meaning that it can last for a period of time.

 You Learn While Doing Other Things

jupiter410

明白了~谢谢terry_run~