1.doubtful从主观角度说,指某人“怀疑”某人某事,后面常接介词of或about,意为对…怀疑; 从客观角度说,指某人某事“令人怀疑”,意为“可疑的,使人产生疑问的”。
2.doubtful作“怀疑的,不能肯定的”解时,可接由where, what, whether等引导的短语或从句。
3.在“It is doubtful”之后常接whether或if引导的从句,用于疑问或否定结构时, doubtful可搭用it的同位结构的that从句。
句型例句
用作定语
▲～+n.
This is a doubtful battle.这是一场胜负难测的战争。
Let's try to clear up our difficult and doubtful points.让我们设法把难处和疑点解决一下。
用作表语
▲S+be+～
The weather looks very doubtful.这天气很靠不住。
Everyone was doubtful at first, but his statement in detail held up.起初大家都怀疑,但他的详细叙述证明情况属实。
▲S+be+～+prep.-phrase
I feel very doubtful about this.我对这点很怀疑。
I feel doubtful about his ability to do the work.我怀疑他有无做这件事的能力。
He was doubtful of the patient's recovery.他怀疑病人是否痊愈。
I am very doubtful of that.我很疑心那件事。
▲S+be+～+wh-to-v I'm doubtful where to go.该往哪里去我心中无底。
▲S+be+～+wh-clause
I feel doubtful what I ought to do.我不知该做什么。
She is doubtful whether her mother really likes the present.她怀疑她母亲是否真喜欢那个礼物。
▲It is/was+～+that/wh-/if-clause
It is doubtful if our resources will hand out for more than two or three days more.我们的资源能否再维持两三天以上,值得怀疑。
It is doubtful whether it is true or not.这事的真假是可疑的。
It is not doubtful that he will give up smoking.他会戒烟是不用怀疑的。
