How to Use a Comma With a Prepositional Phrase

Commas are used in sentences to set off prepositional phrases in some cases, but not always. Nonessential prepositional phrases are set off with commas, while essential ones are not. Use these rules to decide if a phrase is nonessential and where to put the commas.

Instructions

1. Determine the importance of the prepositional phrase to the rest of the sentence. Nonessential prepositional phrases are not necessary to the meaning of the sentence and tend to provide extra information about what the phrase being described.

2. Delete the prepositional phrase from the sentence to see if the same meaning is conveyed without it. If the same meaning is conveyed without the phrase, it is most likely nonessential.

3. Place a comma immediately after the word before the prepositional phrase begins. Then, hit the space bar or manually space if you are writing by hand.

4. Add a comma immediately after the last word of the prepositional phrase.

5. Repeat these steps for more than one nonessential prepositional phrase in the sentence.