Commas are used when two independent clauses are joined with coordinating conjunctions (For, And, Nor, But, Or, Yet, So).
Example: I wanted to play cricket, but I was not feeling well.
However, there are always exceptions to this.
Hope this helps:)
Answer:
A comma must be used when joining two independent clauses with a coordinating conjunction. The comma must precede the coordinating conjunction. For example: The Library of Congress has 838 miles of bookshelves, so you need several days to tour the premises.
Explanation:
on edg. 2020
