Hi! I'm Tim from BBC Learning English
and today I'm going to tell you about three useful words:
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,
'As' and 'since' are more formal than 'because'
and we use them to focus on the result
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