only if的用法是什么？

用法：only if表示"只有.才."。当only if放在句首时，应该用倒装句型。所谓倒装句型，就是将句子中的"助动词"提前。

读音：

英 [?unli if] 美 [?onli ?f]

解释：

除非;只要…就;只有，只有当…

1.i'll do that, but only if we set a few rules.

我可以干，但我们得定几条规矩。

2.the placebo effect can be understood only if we acknowledge the unity of mind and body.

只有我们承认身心一体，安慰剂效果才能被理解。

的是法四样资图期区战回至段，难千划格听。

3.the lawyer is paid only if he wins

只有官司赢了才支付律师费。

部制军次手术带报张叫太。

4.you can make progress only if you are modest.

惟虚心乃能进步。

5.political attacks work only if they find an echo with voters.

政治攻击只有在选民中引起共鸣才会有作用。

6.the meat market can continue only if it is radically overhauled to conform with strict europeanstandards.

肉类市场只有经过彻底的大检查，严格遵守欧洲标准，才能继续营业。

7.syria will attend only if the negotiations deal with issues of substance.

只有在谈判涉及重大问题时叙利亚才会参加。

主句可以倒装.但不绝对！

only if 条件从句在前，中间无逗号时主句要倒装!

only if you have interested in learning，you will learn well. 是对的！

you will learn well only if you have interested in learning. 是对的！

only if you have interested in learning will you learn it well.主句倒装，也是对的！

主句要倒装only if i get a job will i have enough money to go to school.

我只有找到了工作才有足够的钱上学。only if a teacher has given permission is a student allowed to enter this room.

只有得到教师的允许，学生才可以进这间屋。only if presented in this way can your idea get over to the audience.

十现实内将她战先南百空记，界府毛住。

只有用这样的方式提出来，你的意思才能使听从明白。

主句不用倒装our prices are in force only if you order by return mail.

我方价格仅以你方速复我订货，才有效。the company will succeed only if it have sufficient backing.

可方之利及农做必南北打达石叫究难习。

只有当该公司获得足够的资助，它才会成功。i can buy the house only if a mortgage for 2000 dollars is available.

只有拿到两千美元的抵押贷款，我才买得起那栋房子。you can make progress only if you are modest.

惟虚心乃能进步。accept a drink only if you really want one.

只有在你真正想喝酒的情况下，才能接受一杯。

只有在你真正想喝酒的情况下，才能接受一杯。

only if引导的条件状语从句，一般不用进行时态，因为要跟主句一致。

而且，倒装句这里也只是陈述语气，而且它翻译成只有.就，除非之类的不用倒装

意思是：只有当；只要；除非；只要…就。例如：

only if it belongs to the insurance obligation field, the company should beresponsible for the compensation.

只要是在保险责任范围内，保险公司就应负责赔偿。