If a sentence is clear, the comma after an adverbial prepositional phrase at the beginning of a clause is optional. However, the longer the introductory phrase, the more likely you will place a comma after it.
If a sentence is clear, the comma after an adverbial prepositional phrase at the beginning of a clause is optional. However, the longer the introductory phrase, the more likely you will place a comma after it.
In a broad range of situations, it is important to be direct, firm, and assertive.
When in town we enjoy visiting the museums and shops.
In the course of the last few weeks, you’ve done a fantastic job.
In the middle or at the end of a sentence, a comma before or after a prepositional phrase is usually (but not always) unnecessary.
The player withdrew from the competition in the middle of the event.
Contents
1. Quick Review of Adverbial Prepositional Phrases
A prepositional phrase consists of a preposition and an object of that preposition.
He is at home.
Adverbial phrases provide information about when, where, how, why, or how often something happens.
I don’t work on Fridays.
The students are in total silence.
In the middle of an extremely hot night, the robbery took place.
2. Starting a Sentence With an Adverbial Prepositional Phrase
We typically add a comma after long introductory phrases (more than three or four words).
In the context of cybersecurity, we need a more effective strategy to prevent unauthorized access.
However, if an introductory phrase begins with a preposition and the sentence is clear, a comma may not be necessary even if the phrase contains more than four words.
In the very beginning of the movie the bad guy gets shot.
But you can use it for stylistic reasons.
When in town, we always enjoy a delicious meal in our favorite restaurant.
In general, the longer the introductory phrase, the more likely you will use a comma after it.
After a long and exceptionally cold winter in Michigan and the Great Lakes, the warm weather brings more opportunities to play outside.
There are particular situations where a comma may be needed at the start of a sentence. For example, use commas to separate a series of coordinate adverbial phrases.
In the North of Thailand, in the magnificent city of Chiang Mai, you can visit over 300 temples and sacred spaces.
By contrast, do not use a comma to separate two cumulative prepositional phrases (“at the beginning” and “of the book” in the example below).
At the beginning of the book, the writer tries to be creative.
At the beginning, of the book, the writer tries to be creative.
The comma should also be avoided if a verb immediately follows the phrase.
Between your house and my house is the mayor’s mansion.
Between your house and my house, is the mayor’s mansion.
If the introductory phrase is followed by a subordinate clause, use a comma to separate them.
Before school, if there is enough time, I always have breakfast.
In summer, when the weather is too hot, I enjoy going to the beach.
Commas should also be used to avoid confusion.
Last Friday, morning classes were cancelled.
3. Commas In the middle or at the End of a Sentence
We do not typically use commas to set off adverbial prepositional phrases in the middle or at the end of a sentence.
There is a great restaurant around the corner.
We need to finish the project before March because our investors are expecting tangible results.
There are situations, however, where commas are required. For example, use them to signal a strong interruption in mid-sentence or include nonrestrictive information.
Where the mighty Mekong River connects Thailand and Laos, in Southeast Asia, we used to explore the floating markets of the region.
Use also a comma to separate a prepositional phrase from a coordinating conjunction introducing an independent clause.
I love partying with my friends, but my dad doesn’t want me to stay out late.
4. Frequently Used Prepositional Adverbial Phrases
This is a partial list of commonly used prepositional adverbial phrases. You can follow the links below to find more examples and guidelines on how to use commas with them:
- At all times
- At certain times
- At first
- At last
- At some point
- At the beginning
- At the end
- At the instance of
- At the latest
- At the same time
- At the time
- At the time of
- At the time when
- At times
- At various times
- Beyond doubt
- By the end
- By the way
- For a long time now
- For a while now
- For many years now
- For now
- For some time now
- For the long run
- For the long term
- For the moment
- For the short run
- For the short term
- For the time being
- For years now
- In a broad range of situations
- In a number of cases
- In a number of situations
- In a range of situations
- In a wide range of situations
- In case of doubt
- In certain situations
- In conclusion
- In context
- In either case
- In every instance
- In no circumstances
- In some cases
- In some situations
- In that case
- In that situation
- In the beginning
- In the context of
- In the course of
- In the end
- In the first instance
- In the interim
- In the long run
- In the long term
- In the meantime
- In the medium term
- In the middle (of)
- In the Middle Ages
- In the short run
- In the short term
- In the time of
- In these cases
- In these situations
- In this case
- In this instance
- In this situation
- On a number of occasions
- On many occasions
- On numerous occasions
- On occasion
- On several occasions
- On that occasion
- On the occasion of
- On this occasion
- Out of context
- Over the long run
- Over the long term
- Over the short run
- Over the short term
- Under any circumstances
- Under certain circumstances
- Under normal circumstances
- Under these circumstances
- Until now
- Until recently
- Until then
- Up until now
- When in doubt
- Within the context of
- Without a shadow of a doubt
