in time/on time ¹

这三个短语的意思是不相同的。in time 的意思是“及时”（by the due time），“终有一天”“最后”“迟早”或“终于”（eventually, ultimately, at some unspecified time in the future）：

1. I wish you would come in time. 我希望你及时赶到。

2. The journey may seem long and tedious, but we shall get there in time. 旅行似乎是漫长而乏味的，但是我们将及时赶到那里。

3. We were in time for the train. 我们及时赶上了火车。

4. We got to the station just in time to catch the bus. (DAI) 我们及时到达车站, 赶上了公共汽车。

5. Will you be home in time to see the children before they go to bed? (LDCE) 请你在孩子们睡觉之前及时赶到家照料一下他们好吗？

6. In time, all Sam's money was paid back in this way. (New Concept English, Book 2, L. 45) 最后, 萨姆所有的钱都以这种方式被还了回来。

7. If you keep on, you will succeed in time. 如果你坚持下去，总有一天会成功的。

8. In time, all this will be forgotten. 到时候这一切都会被忘记的。

9. The candle-light will in time go out of itself. 烛光到时候会自行熄灭的。

on time 则是指“准时”“准点”“正点”(at the time required, punctually):

1. The train arrived on time. 火车正点到达。

2. Please be here tomorrow on time. 请明天准时到这儿来。

3. My employer will confirm that I was there on time. (NCE 2, L.87) 我的老板可以证明我是准时上班的。

in good time 与 in time 的意思大体相同。但是,有时候还表示“提前”(sooner than necessary; before a set time)的意思,见 time(in good time)。