同学们会在托福作文里常常使用到if从句，但是出错的情况也很容易发生。究竟有哪些被忽略的地方呢? 下面就结合例句说明：

　　If从句中一般不用would：

　　I’d be very frightened if somebody pointed a gun at me.(而非if somebody would point)

　　If I didn’t go to their party， they’d be offended(而非if I wouldn’t go)

　　If …….would可以表示用来请求某人做某事：

　　I would be grateful if you would send me your brochure as soon as possible.

　　“Shall I close the door?” “yes， please， If you would.”

　　Would(‘d) / wouldn’t用于句子的主句(不是if从句)

　　If you took more exercise， you’d (=you would) probably feel healthier.

　　Would you mind if I used your phone?

　　I’m not tired enough to go to bed yet. I wouldn’t sleep.

　　另外，if引导的条件句也能引起倒装，如果要是在作文里用到，也是一个加分点：

　　先看正常语序.

　　It would be a serious setback， if the talks were to fail.

　　If you should need more information， please telephone our main office.

　　If Alex had asked， I would have been able to help.

　　倒装是要省略if

　　it would be a serious setback， were the talks to fail.

　　Should you need more information， please telephone our main office.

　　Had Alex asked， I would have been able to help

　　倒装句比if-从句更加正式.

　　但是在否定句里面，不可以用缩写

　　e.g.

　　Had he not resigned， we should have been forced to sack him(不用hadn’t he…..)