http://www.ck12.org Chapter 11. Punctuation
Use a comma after a dependent clause when it comes before an independent clause. Use a comma with a dependent
clause that comes after an independent clause only if thesubordinating conjunctionimplies contrast (i.e.though,
whereas).
Example 1-If you speak the truth, have a foot in the stirrup.
The subordinating conjunction “if” marks the dependent clause as coming before the independent clause. Place a
comma between the ending of the dependent clause and the beginning of the independent clause.
Example 2- He cancelled his magazine subscriptionbecause he thought the editors no longer addressed important
issues.
The subordinating conjunction “because” does not imply a contrast between the independent clause and the depen-
dent clause. Therefore, we do not use a comma before “because.”
Example 3- Allen is scrambling to finish all of his projects,whereas Amy planned ahead and had everything finished
by last Thursday.
The subordinating conjunction “whereas” implies a contrast between the independent clause and the dependent
clause.
Many sentences begin with a prepositional, gerund, or infinitive phrase that introduces or explains the sentence.
Place a comma between the end of the introductory phrase and the beginning of the subject. If the introductory
phrase is less than four words long, you often do not need to use a comma, although it is never wrong to use one to
be safe.
For definitions and examples of phrases, see Chapter 12, Lesson 2.
Example 1-Togetagoodgrade, you must complete all of your assignments.
The sentence is introduced with an infinitive phrase, and the comma is placed before the subject “you.”
Example 2-Justifyingafault doubles it.
Notice that the gerund phrase is not working as an introductory phrase, but as the subject itself. If a phrase is filling
the role of sentence subject, then we do not place a comma after it.
Review Questions
For each example sentence, insert missing commas or omit incorrectly placed commas.
- I finally found my keys and I got to work just in time.
- Mrs. Contreras threw out her old coffee table, and cleaned the carpet.
- Taking the elevator to the roof we hoped we could see the skyline, and the bay.
- Though Susan wasn’t feel well she went to the store anyway and bought ice cream pizza, and candy.
- I let my neighbor borrow my phone, because she said hers was tapped by the police.