Where to use commas and semicolons can be challenging in many sentences, but how to punctuate around because and however can cause considerable head scratching.
A comma before “because”
Punctuation marks are not little black marks that we randomly sprinkle here and there and hope they fall in the right places. Punctuation marks are intended to guide readers so they correctly understand the meaning of a sentence while also reading it without stumbling.
Most of the time, a comma is appropriate before because, given that the information in the clause that starts with because is not essential to the main thought. You could remove that clause without changing the meaning of the sentence, so it is considered secondary, or nonessential. Notice that in each of the following three sentences, the central idea of the sentence is contained in the main clause, which in these examples is the first half of the sentence. The word because begins a secondary clause that provides extra detail.
Here are examples:
We hold the conference in May, because no one is on vacation then.
Most people ignore their desk phones, because they are squeezed for time.
I really hope to finish the project by Friday, because several people will be out next week.
It often doesn’t even occur to people to insert a comma before because, given that the sentence seems perfectly clear without it, and it might be. Traditionally, we have put a comma there to remove any risk of misreading.
Here are instances where you would not use a comma before because. Inserting it would affect the meaning:
People don’t ignore their desk phones because they are pressed for time; they simply aren’t sitting at their desks very often.
The game was not postponed because of rain; it was postponed because we didn’t have enough players.
I left the meeting because I was sick, not because I was annoyed.
Punctuating however in midsentence
People frequently put commas on both sides of however when it appears in midsentence, but that’s appropriate only in a rare situation. A semicolon is almost always necessary either before or after however, usually before it.
Please get it to me by Thursday; however, Friday morning will be all right.
We don’t have formal approval; however, indications are that we will hear tomorrow.
(If you don’t like the semicolon, you could write, We don’t have approval, but indications are that we will hear soon.)
Semicolons after however
Depending on what the preceding sentence says, a semicolon might be appropriate after however. Notice this sequence:
That’s a great topic for a presentation. The deadline passed for this year, however; please submit it next year.
To help you determine where the semicolon goes, read the sentence aloud, listen to your voice, and notice where the stronger pause is. That’s where the semicolon belongs. We have different degrees of pausing in English, and the semicolon is a stronger mark of separation.
Ken O’Quinn is a professional writing coach and former Associated Press writer who conducts corporate workshops on business writing, persuasive writing, and corporate communications writing. He is the author of Perfect Phrases for Business and is a contributing author of Focus on Them, about leadership.