条件从句

Fergus Clydesdale, head of the department of food science and nutrition at the University of Massachusetts-Amherst, says bluntly that if the dangers from bacterially contaminated chicken were as great as some people believe.

that引导的宾语从句含中有一个if引导的条件状语从句和一个as引导的比较状语从句。

These conditional sentences have two parts: the condition, or si clause

条件句分为两部分：条件，或称si从句，和主句或称结果从句

A nation, which stopped working, would be dead in a fortnight.I should have called to make an airline reservation, but I didn't.The porter ought to have called the fire-brigade as soon as he saw the fire in the stock, which went up in smoke.

动词原形直接用在句子中也被看作是一种虚拟，最常见于正式文体中，动词原形一般用在条件从句中，有时倒装置于句首，同时这种用法也常见于独立句中表达愿望。

This is a nominative absolute structure, which is equal to a conditional clause.

这是一个带分词的独立结构，相当于一个条件从句。

Contract is worth nothing if the event does not take place in the agreed upon period of time.

分析： 这句不算太难。有一个if带头的条件从句。可翻译为

For instance, if it is a subject clause, object clause or predicative clause.

分析从句和短语的功能，例如，是否为主语从句，宾语从句，表语从句等，若是状语，它是表示时间、原因、结果、还是表示条件等等。

It rain tomorrow, you would have to put off the visit to the Yangpu Bridge.

导析：Should位于句首时，省略了if，属于虚拟语气条件从句中的省略。had和were也可以放在句首。

Slide159: I felt that if the day arrived when I was unable to lift one foot up one step and then drag the other painfully after it ---- repeating the process 14 times until, utterly spent, I would be through ---- I could then admit defeat and lie down and die.

L22-25 本句中that 引导了一个宾语从句，这个宾语从句中又包含一个if引导的条件状语从句，而这个条件状语从句中还包含一个由when引导的定语从句。

And if you change your mind, you will not be penalized so long as you have not purchased your ticket and you are not holding a supersaver reservation, or so long as more than seven days remain prior to departure.

要点：这个句子是个主从复合句，其中if引导条件的从句，而主句中包含so long as 引导的三个条件状语从句，分别用and 和or将其连接起来。译文：如果你改变主意也可以，但条件是你没有买票，或者没有预定超级优惠票，或者至少在航班发出前七天告之。

If i had taken my raincoat when i came out this morning, i would not be wet now. I?ohG K,ly\Ka?zO

引导非真实条件从句的连词if在正式文件中有时可以省去， were， had，；t'5}，FP

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。