Should you place a comma before so when it joins two clauses in a sentence? The answer depends on whether the clause introduced by so is an independent or dependent clause. If so begins an independent clause, a comma should precede it, but if it begins a dependent clause, leave it out.
Let’s have a look at how commas are used before so in the middle of a sentence.
Use a Comma with “So” + an Independent Clause
An independent clause is a clause that would convey a complete thought if it were to be set apart as a sentence on its own.