Two independent clauses in the same sentence need both a comma and a co-ordinating conjunction. If the co-ordinating conjunction is omitted this mistake is called a comma splice.
The weather was very bad, I still went fishing.
(no co-ordinating conjunction)
It can be corrected in three ways:
- The weather was very bad, but I still went fishing.
(add a co-ordinating conjunction/but) - The weather was very bad. I still went fishing.
(make two separate sentences) - The weather was very bad; I still went fishing.
(use a semi-colon)
