wonderif的时态

　　I wonder if I should wear a coat or not.

　　我不知道该不该穿外套。

　　Goodness, I wonder if he knows

　　天哪，不知道他是否晓得。

　　I wonder if you could point me in the right direction for the bus station.

　　请问您能指点我到公共汽车站往哪个方向走吗？

　　I wonder if you can help me.

　　不知您是否能帮我的忙？

　　Nothing more was heard from him so that we began to wonder if he was dead.

　　此后再没收到他的消息，于是我们开始怀疑他是不是死了。