VOA一分鐘英語：如何辨析 because，as 和 since？

在英語中，單詞 “because、as” 和 “since” 都可以用來說明一件事發(fā)生的原因，但是這三個單詞強調(diào)的重點有細微的差別。哪個詞語引導(dǎo)的從句著重強調(diào)原因？哪個更注重說明一件事的結(jié)果？在使用這三個詞的時候，有哪些值得注意的地方？
 
Hi, I’m Tim from BBC Learning English. Today I'm going to tell you about three useful words: because, as, and since.
These are all used to give reasons.
Because is more common than as or since and we use it when we want to focus on the reason.
I'm tired because I didn't sleep very well.
When we want to give extra focus to the reason, we can put the because-clause at the beginning of the sentence.
Because my bed is uncomfortable, I'm getting a bad back.
As and since are more formal than because and we use them to focus on the result rather than the reason.
I hope Tom's brought that comic as I wanted to borrow it from him.
Noodles are popular, since they're easy to cook.
We often use as and since clauses at the beginning of a sentence. Just remember to add a comma.
So, as our minute is up, I'll finish recording this video.
 
用法總結(jié)
1 “Because” 比 “as” 和 “since” 更常見。我們用 “because” 來強調(diào)事情的原因。
I'm tired because I didn't sleep very well.
如果想要額外強調(diào)原因，可以將 “because" 引導(dǎo)的從句放在句首。
Because my bed is uncomfortable, I'm getting a bad back.
 
2 “As” 和 “since” 比 “because” 更為正式。我們用 “as” 和 “since” 來強調(diào)事情的結(jié)果。
I hope Tom's brought that comic as I wanted to borrow it from him.
Noodles are popular, since they're easy to cook.
“As” 和 “since” 引導(dǎo)的從句也常用于句首，注意不要忘記在從句后加逗號。
So, as our minute is up, I'll finish recording this video.