Comma, Semicolon, and Colon

Comma
,

Used only for:

• A list:
  • My professor assigned a test, a quiz, and a paper this week. 
• Before a conjunction connecting two independent clauses.
  • My professor assigned a test, a quiz, and a paper this week, and I aced them all!
    (Tip: Not sure if you’re using a conjunction? Remember FANBOYS: For, And, Nor, But, Or, and Yet.)
• Around information that isn’t essential.
  • Because he’s mean, my professor assigned a test, a quiz, and a paper this week, and I aced them all!

Semicolon
;

Used when you want a comma, but need a period.

• Both sides must have a clear connection (they want a comma.)
  • I like coffee. (My preference.) Mom drinks tea. (Her drink preference.)
• Both sides must be complete sentences (they need a period.)
  • I like coffee. Mom prefers tea.
• Ex: I like coffee; Mom prefers tea.

Colon
:

Used like an equals sign.

• One side must be a complete sentence.
  • I have five dogs. 
• The other side is a fragment that expands on the idea.
  • A Lab, a Dalmatian, a German Shepherd, a Pit Bull, and a Corgi. 
• Ex: I have five dogs: a Lab, a Dalmatian, a German Shepherd, a Pitbull, and a Corgi