No. I comma is inserted in the middle of a sentence, statement, a statement that lists several items, or identifying portion of a statement. Where a comma is inserted depends in most cases on the tense of the sentence and whether or not that person needs to pause. Therefore, the word "which" does not always have to have a comma. Please always look at the context of what is being stated and the way it is being expressed. This way you will know whether or not to put a comma. Also put a comma before and after a proper name identified in the middle of a sentence. (example: The supervisor, Bill, will handle it from here).
No. There is no word in English that always requires a comma before it.
It is usually not necessary.
Typically, there is no need for a comma before the word "as." However, using one is not technically wrong, just superfluous.
A comma typically goes before "so" when it is used at the beginning of a sentence to indicate a reason or result. However, when "so" is used as a conjunction in the middle of a sentence, it does not usually need a comma before it.
Before EX: I need eggs, and butter.
not in all cases.
you don't need comma
The general rule is that it doesn't need a comma before it. Example: I like apples as well as guavas.
A comma is typically used before "but" when it connects two independent clauses. However, if "but" is joining phrases within a single sentence, a comma is not necessary.
yes
When which is used to introduce a nonrestrictive adjectivial clause it must it must follow a comma. But there are numerous examples where which does not need to follow a comma. Including: Which melon do you want? I can't tell which melon to buy.
Before. Example: I would have punctuated correctly, but the friendly folks on answers.com were misinformed.