The short answer: you don't need one.
The long answer:
Which is a subordinating conjunction, meaning that when it starts a clause, it makes a dependent clause which is an incomplete sentence.
Grammar dictates the following comma placement in the pairing of clauses:
(Independent Clause = IC, Dependent Clause = DC) IC DC or DC, IC
Since which will start a dependent clause, provided that you put the independent clause first, you need not place a comma on behalf of the word which. If, however, the dependent clause goes first, you must place a comma after the entire clause, not just the word which.
The comma typically goes before "which" when introducing a nonrestrictive clause (provides additional information that is not essential to the meaning of the sentence). It is not needed before "which" when introducing a restrictive clause (essential information that is needed to understand the sentence).
It could go either ways?
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.
A comma is generally not needed before "because" in a sentence. However, if "because" is introducing a dependent clause, a comma can be used after it to separate it from the main clause.
The comma should come before the word "but" when it is used to separate two independent clauses. For example: "I wanted to go to the store, but it started raining."
No, a comma is not always necessary before "which" in a sentence. Use a comma before "which" when introducing a nonessential clause, but do not use a comma before "which" when introducing an essential clause.
No, a comma does not go before the word 'in'.
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.
It could go either ways?
Not necessarily. There is no word in English that requires a comma before or after it.
A comma is generally not needed before "because" in a sentence. However, if "because" is introducing a dependent clause, a comma can be used after it to separate it from the main clause.
no
No.
After
after
Before
The comma typically goes before the parentheses if it is part of the main sentence. If the parentheses contain a complete sentence, the period or other punctuation mark will typically go inside the parentheses.
A comma typically goes before the word "so" when it is used to introduce a clause or indicate a relationship between two clauses. However, in some cases, the comma may be omitted if the sentence is brief and the meaning clear without it.