Prepositional phrases are phrases that start with a preposition. Yes, we should all be grammatical experts, but there are translators that use the force more than their style book. It’s really a personality thing. So I feel the need to be explicit–don’t worry, not so explicit that I’m going to bother translating for translators.
OK, now for the rules: to use a comma or not to use a comma, that is the question.
Comma, please.
- Non-essential prepositional phrases.
- Test: Take out the prepositional phrase. If you’re left with nonsense, it’s essential. Otherwise, not so much.
- Check it out: Desert oases are the main, in many cases the only, source of water in the region.
- Remember: Commas that isolate phrases come in pairs. If the prepositional phrase is in the middle of the sentence, you need one before the prepositional phrase and another one after.
- Long introductory prepositional phrases. (Some style books say 4+ words, others say 5+, but you get the idea.)
- Test: Does the long prepositional phrase come first? Yes? Stick a comma after it.
- Check it out: In every case that I can think of, coffee is a good idea.
- Note: In Spanish the length doesn’t matter! All introductory prepositional phrases get a comma. The exception is when the prepositional phrase is just announcing the topic.
- Check it out: Del chocolate, puedo hablar por horas. / Del chocolate puedo hablar por horas.
No comma, thank you.
- Essential prepositional phrases
- Test: Take out the prepositional phrase and the meaning is lost or completely altered.
- Check it out: There’s a crocodile in the back yard!
- In between more than one introductory prepositional phrase
- Test: Does it sound stupid and stilted?
- So wrong: On the edge, of the dock, she waited, for the ship to return.
And that’s it for today’s review. There are more comma rules relating to prepositions, I’m sure, but these are the ones that really stand out. Feel free to fill in the rest of the rules in the comments.
Enjoy the article? Please subscribe.
Subscribe to Mark it Right by email
Mark it Right 
What about several non-essential prepositional phrases in in a row?
example
Years after most people were happily blogging away, over cups of coffee, in their kitchens; I was still slogging across town to send an email.
LikeLike
Regarding your paragraph:
” ◦Test: Take out the prepositional phrase. If your left with nonsense, it’s essential. Otherwise, not so much.”
The word should be “you’re” indicating a contraction of the words “you are.”
“Your” is the possessive form of “you.”
LikeLike
Thanks!
LikeLike
I used this post to edit a sentence for a client – very helpful. What stylebook do you use?
LikeLike
Michele: For English, I like “The Scott, Foresman Handbook for Writers” because it gives you the AP and the CMS rules, and those are the main style books I need to reference. I’m also a fan of Grammar Girl; she references several style books and gives clear explanations.
For Spanish I use the Real Academia España.
LikeLike
Grazie!
LikeLike
What about this: “By planning for, rather than reacting to, climate change, people can…”
Does that need dashes instead of commas? “By planning for–rather than reacting to–climate change, people can…”
Are “planning for” and “reacting to” even prepositional phrases? I’m stumped and irritated with this sentence!
LikeLike