Semicolons

1. Use a semicolon between two clauses of a compound sentence when they are not connected by a conjunction, unless they are very short and used informally.

The trip was long and tiring; we fell asleep almost at once.
(These two independent clauses could also be separated into two sentences or joined by a coordinating conjunction such as and.)

The children ran, they shouted, they squealed with excitement.
(These clauses are so short that they work well with commas as if items in a series.)

2. Use a semicolon between clauses of a compound sentence which are joined by conjunctive adverbs.

It was raining; however, everyone had brought an umbrella.

3. Use a semicolon if clauses joined by conjunctions are very long, or when the clauses have commas within them. The semicolon in this case is used for clarification.

4. Use a semicolon before as, namely, or thus when these words are used to introduce examples.

Three girls were given an award; namely, Susan Whitehead, Meredith Smith, and Sonya Rogers.

More punctuation notes