Writing: FANBOYS

FANBOYS is a handy mnemonic device for remembering the coordinating conjunctions: For, And, Nor, But, Or, Yet, So. These words function as connectors. They can connect words, phrases, and clauses, like this:
Words: I am almost dressed and ready.
Phrases: My socks are in the living room or under my bed.
Clauses: They smell really bad, so they will be easy to find.
Notice the comma in the final example. You should always have a comma before FANBOYS that join two independent clauses (two subjects and two verbs that make up two complete thoughts). Look carefully at the next two sentences to see two independent clauses separated by comma + FANBOYS.

If you do not have two subjects and two verbs separated by the FANBOYS, you do not need to insert the comma before the FANBOYS. In other words, if the second grouping of words isn’t a complete thought, don’t use a comma. Try reading the words after FANBOYS all by themselves. Do they make a complete thought?