399. Use a Comma After a Subordinate Clause

A subordinate clause is a group of words that shows action but cannot stand alone. When you begin a sentence with a subordinating conjunction, you are beginning your sentence with a subordinate clause.

Here are five common subordinating conjunctions: after, before, although, while, until
Whenever you begin a sentence with one of these words, you are writing a subordinate clause.
After we finish breakfast
Before we go to school
Although it is not raining
While you were sleeping
Until the bell rings
Notice that each clause begins with a subordinating conjunction and includes an action verb. However, each clause does not make sense by itself.

We must add an independent clause to each subordinate clause to make a complete sentence, like this:
After we finish breakfast, we can take a walk.
Before we go to school, we should fold the laundry.
Although it is not raining, we should still take an umbrella.
While you were sleeping, the cat broke the picture frame.
Until the bell rings, you must remain in your seats.

When you begin a sentence with a subordinating conjunction, you are writing a subordinate clause. You must put a comma after the subordinate clause and add an independent clause to make a complete sentence.

▶Now it’s your turn. Where should you place a comma in this sentence? While you wash the lettuce I will cut up the tomatoes. Can you find the subordinate clause at the beginning of the sentence? Did you put a comma after the subordinate clause? Good for you!