Difference between "as", "since", and "because"
As we've known, "as", "since" and "because" are all used to express the reason. However, there certainly are some differences between them. What are they? And why we can always use "because" in place of "as", "since" while we cannot always use "as" and "since" in place of "because". Can anybody know the answer? Please help me. Thanks in advance.

Question

Answer

I wouldn't say "since" means the same as "as" and "because". "As" and "because" are basically exact in meaning. It's just that "as" is more formal. It makes the sentence sound more 'official'.

But "since" has a slightly different meaning, even though I can't explain exactly WHAT. The best answer I can give is that you normally use "since" at the beginning of a sentence, and "as" or "because" in the middle of a sentence.

So, it would be normal to say: "Since the parking is so expensive, I'll just stay home" while it would be weird (but not wrong) to say "I'll just stay home because the parking is so expensive".

Answer

"As" and "since" have other meanings and usages.  "Because" does not; it has only one meaning and usage.