doubtful

adj.

1. 拿不定主意；不确定；怀疑
   not sure; uncertain and feeling doubt
   1. Rose was doubtful about the whole idea.
      罗斯对整个设想持怀疑态度。
   2. He was doubtful about accepting extra work.
      他拿不定主意是否接受额外工作。
2. 未必；难说；不大可能
   unlikely; not probable
   1. It's doubtful if this painting is a Picasso.
      这未必就是毕加索的画。
   2. With her injuries it's doubtful that she'll ever walk again.
      她多处受伤，今后能否行走还很难说。
   3. It's doubtful whether the car will last another year.
      这辆汽车未必还能用上一年。
   4. He is injured and is doubtful for the game tomorrow (= unlikely to play) .
      他受了伤，明天未必能参赛。
3. 不明朗；悬而未定；可能变糟
   uncertain and likely to get worse
   1. At the beginning of the war things were looking very doubtful.
      战争刚开始时，形势看上去很不明朗。
4. 低劣的；未必是真的；靠不住的
   of low value; probably not genuine or of a quality that you can rely on
   1. This wine is of doubtful quality.
      这酒的质量有问题。

1. ADJ-GRADED 未必的;不大可能的
   If it is doubtful that something will happen, it seems unlikely to happen or you are uncertain whether it will happen.
   1. For a time it seemed doubtful that he would move at all...
      有一段时间他似乎根本不会搬家。
   2. It is doubtful whether Tweed, even with his fluent French, passed for one of the locals...
      尽管特威德能说一口流利的法语，他是否能被当作当地人还很难说。
   3. Whether the authorities will allow inspection is highly doubtful.
      当局是否允许检查还是个大问号。
2. ADJ-GRADED 怀疑的;疑惑的;拿不定主意的
   If you are doubtful about something, you feel unsure or uncertain about it.
   1. I was still very doubtful about the chances for success...
      我对能否成功仍然深表怀疑。
   2. Why did he sound so doubtful?
      为什么他听上去如此不确定？
3. ADJ-GRADED (质量或价值)低劣的，不可靠
   If you say that something is of doubtful quality or value, you mean that it is of low quality or value.
   1. ...selling something that is overpriced or of doubtful quality...
      售卖漫天要价或质量低劣的东西
   2. They also seemed of very doubtful value.
      它们好像也没有多大价值。
   3. ...information that he described as having doubtful reliability.
      据他所称未必可靠的消息
4. ADJ-GRADED (通常指运动员因伤)不大可能参加（比赛）的
   If a sports player is doubtful for a match or event, he or she seems unlikely to play, usually because of injury.
   1. Forsyth is doubtful for tonight's game with a badly bruised leg.
      福赛斯腿部严重擦伤，不大可能参加今晚的比赛。

Do not confuse doubtful, dubious, and suspicious. If you feel doubtful about something, you are unsure about it or about whether it will happen or be successful. Do you feel insecure and doubtful about your ability?... It was doubtful he would ever see her again. If you are dubious about something, you are not sure whether it is the right thing to do. Alison sounded very dubious... The men in charge were a bit dubious about taking women on. If you describe something as dubious, you think it is not completely honest, safe, or reliable. ...his dubious abilities as a teacher. If you are suspicious of a person, you do not trust them and think they might be involved in something dishonest or illegal. I am suspicious of his intentions... Miss Lenaut had grown suspicious. If you describe something as suspicious, it suggests behaviour that is dishonest, illegal, or dangerous. He listened for any suspicious sounds. ...in suspicious circumstances.
不要混淆 doubtful, dubious, suspicious。doubtful 指不确定某事或不确定其是否会发生或成功：Do you feel insecure and doubtful about your ability（你对自己的能力缺乏信心，抱有怀疑吗），It was doubtful he would ever see her again（他会不会再见到她还说不准）。dubious 指拿不准做某事是否正确：Alison sounded very dubious（艾利森听上去犹豫不决），The men in charge were a bit dubious about taking women on（几位男性负责人有点儿拿不准要不要招女员工）。dubious 还可指某事物不完全可信、安全或可靠：his dubious abilities as a teacher（他的教学能力令人怀疑）。suspicious 指不信任某人，怀疑其从事欺骗性或不法活动：I am suspicious of his intentions（我怀疑他动机不纯），Miss Lenaut had grown suspicious（莱诺小姐已经起了疑心）。suspicious 还可指某人的行为可疑、不诚实、涉及非法或具有危险性：He listened for any suspicious sounds（他注意倾听任何可疑的声音），in suspicious circumstances（在可疑的情势下）。

1. For a time it seemed doubtful that he would move at all
   有一段时间他似乎根本不会搬家。
2. It is doubtful whether Tweed, even with his fluent French, passed for one of the locals
   尽管特威德能说一口流利的法语，他是否能被当作当地人还很难说。
3. Whether the authorities will allow inspection is highly doubtful.
   当局是否允许检查还是个大问号。
4. I was still very doubtful about the chances for success
   我对能否成功仍然深表怀疑。
5. Why did he sound so doubtful?
   为什么他听上去如此不确定？
6. They also seemed of very doubtful value.
   它们好像也没有多大价值。
7. Forsyth is doubtful for tonight's game with a badly bruised leg.
   福赛斯腿部严重擦伤，不大可能参加今晚的比赛。
8. Ecologists argue that the benefits of treating sewage with disinfectants are doubtful.
   生态学家认为用消毒剂处理污水是否有益值得怀疑。
9. They paused at the top of the stairs, doubtful as to which way to go next
   他们在楼梯顶部停住了，不知道接下来该往哪边走。
10. As soon as he finished, his supporters applauded vigorously, but most of the masses were taken aback and exchanged doubtful glances.
    他的话完了，他的几个支持者拼命地鼓掌，而更多的人却噤若寒蝉，面面相觑。
11. The speaker was clearly playing to the gallery when he uttered so many doubtful jokes.
    演说者讲了这么多似是而非的笑话，显然是迎合低级趣味。
12. This is a doubtful battle.
    这是一场胜负难测的战争。
13. I feel doubtful about his ability to do the work.
    我怀疑他有无做这件事的能力。
14. His future success is doubtful.
    他未来的成功值得怀疑。
15. 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。
16. I am doubtful of the team's chance in the match.
    我怀疑这支球队在这场比赛中获胜的可能性。
17. This is a doubtful connection and extremely complicated marriage.
    这一对的关系很难预测，婚姻也会极端复杂。
18. You know I had been doubtful about his sharing rooms with you.
    你知道，我对他和你住在一起一向不放心。
19. I am doubtful about what he said.
    我对他说的话感到很怀疑。
20. But he was doubtful about the usefulness of the research.
    但是他对该研究的用处表示怀疑。
21. I was doubtful, but followed her through the dark streets.
    我有些怀疑，但还是跟着她穿过了黑暗的大街。
22. It's very doubtful he should finish the task on time.
    他竟然按时完成了任务，这很令人怀疑。
23. It's doubtful that he has become the manager of that firm.
    他已经当上了那个公司的经理，这值得怀疑。
24. Still, I remain doubtful.
    不过，我的疑虑还没有完全消除。
25. He is a doubtful character.
    他是个可疑的人物。
26. He says he can do it, but I'm rather doubtful.
    他说他能做它，但我感到相当感到怀疑。
27. They are doubtful whether he can afford it.
    他们怀疑他是否能担负得起。
28. Are you doubtful of success?
    你怀疑是否能成功？
29. This logic can explain some phenomena, however, it led many theoretical doubtful points.
    这个逻辑合理地解释了一些现象，但是也制造了诸多理论疑点。
30. You may be doubtful about whether doing this can help, but your chart shows otherwise.
    你可能会怀疑这么做是否会有帮助，但是你的图表体现的是另外一个方面。