Because\As\Since的用法

Because, as, since

Reasons
Because, as and since are all used to give reasons.

I'm tired because I didn't sleep well.

I'm tired as I didn't sleep well.

I'm tired since I didn't sleep well.
Because

Because focuses on the reason for something.It is more common than as or since.

We can put the because clause at the beginning of the sentence. When we do so, we need to add a comma between the two clauses.

You're reading this because you want to learn English.

They won't be here because they're on holiday.

Because you want to learn English, you're reading this.

Because they're on holiday, they won't be here.

As and since

As and since focus on the result of something rather than the reason for it.

We can put the as or since clause at the beginning of the sentence. When we do so, we need to add a comma between the two clauses.

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 I wanted to borrow that comic, I hope Tom's brought it with him.

Since they're easy to cook, noodles are popular.

Hi! I'm Tim from BBC Learning English and 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 the sentence. Just remember to add a comma.

So, as our minute is up, I'll finish recording this video.