34a. Independent clauses not joined with a coordinating conjunction
34aUse a semicolon between closely related independent clauses not joined with a coordinating conjunction.
When two independent clauses appear in one sentence, they are usually linked with a comma and a coordinating conjunction (and, but, or, nor, for, so, yet). If the clauses are closely related and the relation is clear without a conjunction, they may be linked with a semicolon instead.
In film, a low-angle shot makes the subject look powerful; a high-angle shot does just the opposite.
A semicolon must be used whenever a coordinating conjunction has been omitted between independent clauses. To use merely a comma creates a type of run-on sentence known as a comma splice. (See 20.)
