“because”同“since”的分別.................

As/ since 與because 同樣係連接詞, 亦都解作「因為」, 但分別在於它們的用法和含意。以下係參考一位文法書Practical English Usage 作者Michael Swan的解釋。英文部份係原稿, 中文解釋係我附加上去。


1) as and since

As and since are used when the reason is already known to the listener/ reader, or when it is not the most important part of the sentence. As- and since- clauses often come at the beginning of sentences.
當我地要提及的原因係大家已知, 就會用as and since, 或者當這個原因並非某句子的重點。因此, as and since的 clause 通常會被放在句子的開端。

As it’s raining again, we‘ll have to stay at home.
Since he had not paid his bill, his electricity was cut off.

As- and since-clauses are relatively formal: in an informal style, the same ideas are often expressed with so.

2) because

Because puts more emphasis on the reason, and most often introduces new information which is not known to the listener/ reader.
如果改用Because時, 一般係要去強調所提及之原因, 或者此原因係對方未知的。

Because I was ill for six months, I lost my job.

When the reason is the most important part of the sentence, the because-clause usually comes at the end. It can also stand alone. Since and as cannot be used like this.
由於此原因係句子的重點, 所以通常留在句子的末端。甚至可以用作獨立的句子。

Why am I leaving? I‘m leaving because I‘m fed up!
(NOT…I‘m leaving as/since I‘m fed up!)

Why are you laughing? Because you look so funny.

沒有分別，但如果since後面是年份的話，就解自從的意思。

since
ad.(常用於現在完成式或過去完成式)
1.此後;從那時到現在
She left school three years ago and has worked as a nurse ever since.
她三年前畢業,從那時起便一直當護士。
2. 之前,以前




prep.
1. (常用於現在完成式或過去完成式)自...以來,從...至今
I haven't heard from him since last year.
我自去年以來未曾收到過他的信。


conj.
1. (常用於現在完成式或過去完成式)自...以來,從...至今
It's been ten years since they married.
他們結婚到現在已經十年了。
2. 既然;因為,由於
He must have taken the book since it isn't here.
他一定是把書拿走了,因為書已不在這裡了。

conj.
1. 因為
He is absent because he is ill.
他因病缺席。