一个句子中能不能同时有助动词和情态动词出现?

一个句子中能不能同时有助动词和情态动词出现?

除非是重句，比如：don't do that because you can't finish。除此，单句来讲就不可以

动词表示动作形态，但英语里有些动词并不表示动作形态，而是协助主动词表示时态（tenses）或语态（voices）。这些动词如“ do, is, have”等，叫助动词（auxiliary verbs）。另外有些动词如“can, will, may, must”等，则可协助动词表示语气或情态，叫情态动词（modal verbs）。 　　助动词和情态动词都是特殊动词，非常有用。没有了它们，疑问句不能成立，否定句也难形成。没有了“have, has, had”完成时态（perfect tenses）无法存在；没有了“be, is, are, am, been, was, were, being”，何来被动语态（the passive voice）？请看下列例子，就知道梗概了： ● -what do you do every day? 　 -i teach every day. ● -can they speak english? 　 -yes, they can. ● -will he do it? 　 -no, he won't. ● -john lived here before. 　 -john did not live here before. ● -betty has completed her work on time. 　 -she is really good. ● -after i had eaten my breakfast, i went to office. 　 -how about nancy? did she do the same? ● -jason is writing a new book. 　 -a new book is being written by sam, too. ● -the cat caught a rat. 　 -a rat was caught by a cat. 　　此外，助动词和情态动词还有下列用途： 　　㈠构成疑问句附加语，如： ● mr chen has not become a businessman, has he? ● jason's lectures are clear and easy-to-understand, aren't they? 　　㈡构成简短答语，如： ● -who can answer this question? 　 -sam can. ● -will you help us with the gardening? 　 yes, i will. /no, i won't. ● -i have seen that film before. 　 -so have i. ● -william isn't a hypocrite. 　 -neither is his wife. 　　㈢构成省略句，如： ● i can't understand him. can you ? ● the boss doesn't often come to the factory and when he does, it is generally on sunday