要是他们肯听他的话就好了，我相信他们能解决问题。

___If ___only they'd listen to him, I'm sure they could work it out.

要是我更小心一点就好了。

___If ___only I had been more careful.

要是你打电话给我就好了，我们本可以避免这个误解。

___If ___only you had called me, we could have avoided the misunderstanding.