since

1. PREP You use since when you are mentioning a time or event in the past and indicating that a situation has continued from then until now. 自…以来; 从…以后

He's been in exile in India since 1959. 他自1959年以来一直流亡印度。

She had a sort of breakdown some years ago, and since then she has been very shy. 她几年前曾遭遇精神崩溃，从那以后她一直怯生生的。

2. ADV Since is also an adverb. 自那时起[ADV with v]

They worked together in the 1960s, and have kept in contact ever since. 他们在20世纪60年代曾一起工作，自那时起就一直保持着联系。

3. CONJ Since is also a conjunction. 自…以来

I've earned my own living since I was seven, doing all kinds of jobs. 我自从7岁就自己谋生，做各种各样的工作。

4. PREP You use since to mention a time or event in the past when you are describing an event or situation that has happened after that time. 自…以来

The percentage increase in reported crime this year is the highest since the war. 今年报道的犯罪增长率是该战争以来最高的。

5. CONJ Since is also a conjunction. 自…以来

So much has changed in the sport since I was a teenager. 自我十几岁以来，该项运动发生了很大变化。

Since I have become a mother, the sound of children's voices has lost its charm. 我当了母亲之后，孩子的声音就失去了魅力。

6. ADV When you are talking about an event or situation in the past, you use since to indicate that another event happened at some point later in time. 此后; 后来[ADV with v]

About six thousand people were arrested, several hundred of whom have since been released. 约六千人被逮捕，不过他们中有几百人后来被释放了。

7. CONJ You use since to introduce reasons or explanations. 由于; 既然

I'm forever on a diet, since I put on weight easily. 我一直在节食，因为我的体重很容易增加。