例句辨析：
only if
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。
3、The lawyer is paid only if he wins
只有官司赢了才支付律师费。
4、You can make progress only if you are modest.
惟虚心乃能进步。
will win the race only if you train hard.
只要你努力训练，你会赢得比赛。
if only
1、If only it were that simple!
要是那么简单就好了！
2、If only someone could help me!
有谁能帮助我就好了！
3、If only I could get some sleep, I would be able to cope.
要是能睡上一会儿，我就能应付了。
4、If only I could be master of this subject.
我多么希望能精通这门学科。
only I would driver the car.
要是我会开车就好了