Definition: A comma separates elements in a sentence, such as items in a list or series, but it also shows that those elements are connected to each other within the same sentence. One use of the comma is to separate three or more words, phrases, or clauses in a list or series. …

Use a comma between two complete sentences joined with a coordinating conjunction. There are 7 coordinating conjunctions: and, but, or, nor, yet, so, for. Common mistake: Comma splice—Using a comma to join two complete sentences without a conjunction. Incorrect—[Complete sentence],[complete sentence].

Rule: Use a comma between two independent clauses when conjunctions such as and, or, but, for, nor connect them. Example: I have painted the entire house, but she is still working on sanding the floors. Rule: If the clauses are short (your call), then leave out the comma. Example: I painted and he sanded.

Joining two sentences with a past participle

1. The car was damaged in the accident.
2. Damaged in the accident, the car needed a new door.
3. The boat was tossed up and down.
4. Tossed up and down, the boat developed a leak.
5. I was impressed by the team.
6. Impressed by the team, I stayed for the whole match.

The word “yes” can be an adverb, an interjection or several other parts of speech. That is, you will usually need a comma after “yes” when the word starts a sentence. Alternately, and if you really want to emphasize the word, you may follow it with a period instead.

This final comma, known as an Oxford or serial comma, is useful in a complex series of elements or phrases but is often considered unnecessary in a simple series such as in the example above. It usually comes down to a style choice by the writer. The semicolon (;) is used to connect independent clauses.