doubt的用法是什麽？

doubt是個常用詞，也是歷年高考經常考查的詞語之壹。doubt既可用作動詞，也可用作名詞。現將其用法歸納如下。壹、doubt用作動詞1. doubt+名詞或代詞。例如：I doubt his word.我懷疑他的話。They doubted him before.他們以前曾經懷疑過他。2. doubt+賓語從句（1）在否定句和疑問句中，doubt後面接that引導的賓語從句。例如：I don”t doubt that he can finishthe task on time. 我相信他能按時完成任務。Do you doubt that she willsucceed? 妳懷疑她會成功嗎？（2）在肯定句中，doubt後面壹般接whether或if引導的賓語從句。例如：I doubt whether they can swimacross the river. 我懷疑他們能否遊過河去。He doubts if she will keep herword. 他不敢肯定她是否會遵守諾言。註意：在肯定句中，doubt後面也可以接that引導的賓語從句，但表示疑慮較大或“不相信”。例如：We doubt that they can completethe work ahead of time. 我們不相信他們能提前完成這項工作。I doubt that he will come.我看他未必會來。二、doubt用作名詞1. doubt常與about/of/as to/on等介詞連用。例如：There is no doubt aboutit. 此事無可懷疑。I have no doubt of hisability. 對於他的能力我毫不懷疑。She has her doubts as to thisbeing true. 她懷疑這事是否真實。No one has any doubt on thispoint. 這壹點沒有人會懷疑。2. doubt後面接同位語從句（1）doubt用在否定句中，後面接that引導的同位語從句。例如：I have no doubt that he willsucceed. 我相信他會成功的。There is no doubt that they willagree with you on this matter. 毫無疑問，他們在這件事上會同意妳的意見的。（2）doubt用在肯定句中，後面接whether引導的同位語從句。註意不可以用if替換whether。例如：He had his doubts whether theywould give him another chance to have a try. 他不能肯定他們是否會再給他壹次機會試壹試。There is some doubt whether theirfootball team will win the match. 他們的足球隊會不會贏得這場比賽還不能肯定。3. 由doubt組成的壹些短語（1）indoubt懷疑；拿不定主意。例如：We are in doubt(about) what to donext. 我們不知道下壹步要做什麽。When in doubt about the meaningof a word, consult the dictionary. 當妳對壹個詞的意義沒有把握時，就查壹下詞典。（2）no/without/beyond doubt無疑地；必定；當然。例如：It is no doubt difficult.這無疑是困難的。No doubt he didn”t mean to hurtyou. 他肯定不是有意傷害妳的。Without doubt this is thebest. 無可置疑，這是最好的。Beyond doubt he will give yousome advice on your study. 毫無疑問，他會給妳的學習作壹些指導的。（3）makeno doubt of 對……毫不懷疑。例如：We make no doubt of hissincerity. 我們對他的誠意毫不懷疑。She made no doubt of what he hadsaid. 她對他所說的話毫不懷疑。（4）throw/cast doubt on使人對……產生懷疑。例如：Galileo”s experiments threwdoubt on Aristotle”s theory of falling objects. 伽利略的實驗使人們對亞裏士多德的落體理論產生了懷疑。What he had done cast doubt onhis honesty. 他的所作所為使人們對他的誠實產生了懷疑。