Comma Faults

Bill Situ

English and ESL Instructor

A comma fault (also known as a comma splice) is a grammatical error where there is a comma in between two independent clauses:

     It is almost eight o'clock, I cannot make it to school on time.

The sentence above has two clauses:

     Clause 1: It is almost eight o'clock.

     Clause 2: I cannot make it to school on time.

Both clauses are independent clauses, which means that they can stand alone as sentences. Therefore, using a comma between these clauses would be a comma fault. To fix this problem, we can do the following:

     Solution 1 — Use a semicolon:

          It is almost eight o'clock; I cannot make it to school on time.

     Solution 2 — Write the two clauses as separate sentences: 

          It is almost eight o'clock. I cannot make it to school on time.

     Solution 3 — Use a conjunction:

          It is almost eight o'clock and I cannot make it to school on time.

Whenever you decide whether you can use a comma or not, you need to first look at the clauses before and after the comma. If both can stand alone as sentences like the example above, then it is not proper to use a comma. If one or both clauses are dependent (meaning they cannot stand alone as sentences), then you need to use a comma:

     When it was almost eight o'clock, I realized I could not make it on time. (Clause 1 is dependent)