她很小时，就开始学习弹钢琴。
While (I was) at college, I began to know him, a strange but able student.我在上大学时就开始认识他，一个奇怪但有能力的学生。
When arriving, send me a telegram. (When you arrive, send me a telegram.)到达之后，来个电报。
Before leaving, turn off all the lights. (Before you leave, turn off all the lights.)走之前，请关闭所有的灯。
Don’t come in until (you are) asked to.不叫你请你不要进来。
Whenever (it is )possible, you should come and help.不管什么时候只要有可能就来帮忙。
You should let us know the result as soon as(it is) possible.你应尽快让我们知道结果。
注：as在引导时间状语从句时，没有这种省略现象。我们不可说As walking, she found a nice shining thing on the ground.
二、地点状语从句中的省略地点状语从句的省略常用下列结构：where(ver) possible, where(ver) necessary,Lay these books where possible you can find them easily.把这些书放在你可能容易找到的地方。
Put in articles wherever necessary in the following passages.在下列文章中需要的地方填入冠词。
三、条件状语从句中的省略常用的句型是：if necessary, if possible, if true, if anyone等。如：Send the goods now if (they are) ready.
货物如果准备好了，请送过来。He will come if (he is) asked.如果叫他来，他就来。
If (it is) necessary, ring me at home.如果有必要，朝我家里打电话。
Come along with me if (it is) possible.如果有可能和我一起去吧。
If (it is) true, this will casue us a lot of trouble.如果是真的，这会给我们带来很多麻烦。
There are few people nowadays, if (there are) any, who remember him.很少有人能记起他。
You should stay where you are, unless (you are) asked to leave.你应呆在你现在的地方不动，除非叫你动。
四、让步状语从句中的省略
He is a good man, though sometimes (he is) rather dull.他真是个好人，尽管有时有点无聊。Even if (I am ) invited to, I won’t go to such a bad lecture.即使邀我去，我都不想听如此坏的报告。
五、比较状语从句中的省略
She can play the piano just as wonderfully as you (do).她钢琴弹的我你弹的一样好。She has finished the work earlier than (it has been ) expected.她完成得比预期要早。
本文来自：逍遥右脑记忆 https://www.jiyifa.com/chuzhong/1131190.html
相关阅读：别整天只顾喊累 学学工作生活平衡法