Clauses and phrases of reason
When you want to explain why something happens, you can use a clause of reason introduced by a conjunction (because, as, since) or a phrase introduced by “because of”.
- Daniel joined the English Drama Club because / as/ since he wanted to improve his intonation.
- As / Since/ Because Daniel wanted to improve his intonation, he joined the English Drama club.
Use a comma when the clause or phrase of reason is at the begging of the sentence.
- Since I cleaned my bedroom yesterday, I don’t need to clean it today.
As and since are used when the reason is already known to the listener.
- As it is raining again, we will have to cancel the match.
As and since-clauses are relatively formal. In an informal style, the same idea can be expressed with so.
- It is raining again, so we will have to cancel the match.
Because-clauses are used to give information which isn’t already known to the reader or listener.
- Because he had not paid the bill, his electricity was cut off.
Note that a because-clause can stand alone. As and since-clauses cannot be used like this.
- “Why are you looking at her like that?” “Because she smiled at me.” (NOT As she smiled at me.) (NOT Since she smiled at me.)