3.拒绝帮助对方
如：Can you help me with the math problem?
(1) You are driving me mad.
(2) I don't want to be interrupted before I finish my term paper. (3) * I'd like to, but I've got an appointment with a professor at two o'clock.
(4) * I wish I could, but I afraid that I've got to rush now.
（5）*I'm afraid I just ran out of time.
4. 拒绝对方的提议或要求 (1) 拒绝对方的提议
如：Shall we go to the seaside for the weekend? ① I'd like to, but my paper is due next Monday.
② I'll go if you really want me to, but I want to have a good rest at home.
(2) 拒绝对方的要求
如： Try not to make mistakes in your exam.
① * Well, easier said than done.
否定句型在这类题型中，最重要的线索是抓住否定性的关键词。值得注意的是这类题一般都不是以明显的
否定方式出现的，所以需要考生多加注意。包含否定性的关键有： 否定副词和形容词：hardly, rarely, little, seldom, few, never等。 否定代词和连词：nothing, nobody, neither, nor, none等。 否定前缀和否定后缀：im-, un-, dis-, non-, -less等。
表否定意义的其他词：fail, miss, avoid, deny, refuse, doubt, far from, anything but, instead of, rather than等。