by Dianna Booher

What people do intuitively with their voice inflection often bewilders them in writing. The challenge is translating voice inflection to the page, post, or tweet.   To be more dramatic about it: cut a comma and you may destroy someone’s career or see them in court.

To repeat: A comma tells a reader to pause. The absence of a comma means that a reader should keep going full speed ahead. If you set off the middle or final part of a sentence with a comma, you’re telling a reader that part of the sentence is nonessential—that it adds information but is not essential to the meaning of the sentence.

Test:  If you can’t remove that part of the sentence without changing the meaning of what’s left, then don’t set that part off with commas.

Try it: “Pudge prefers to work with clients who have multiyear contracts.”

Question: Do you need a comma to set off the who clause in the above sentence?

Try the rule: Omit the final part to verify that it’s nonessential and that what’s left of the sentence has the same meaning: “Pudge prefers to work with clients.” That remaining part has a different meaning. Pudge doesn’t prefer just ANY clients; he’s particular. He prefers clients with multiyear contracts. “Who have multiyear contracts” is essential to the meaning of the sentence. Result: It is incorrect to set that part off with a comma.

Try another example: “Brunhilda submitted our proposal, which has a strong chance of winning, to the European client last week.”

Question: Do you need commas around the which clause to set it off from the rest of the sentence?

Try the rule again: Omit the part between the commas to verify that it’s nonessential. Does the meaning of what remains change?  “Brunhilda submitted our proposal to the European client last week.”  No.  Result:  Which has a strong chance of winning is just additional information––nonessential to the meaning of proposal. The commas are used correctly.

Consider how you would inflect your voice and where you would pause in the following sentences. (Although I’m not suggesting that you learn to punctuate by voice inflection, that system will help you determine the meaning in your own sentences and understand the use of commas to set off nonessential elements.)

I have a neighbor who speaks Russian. (Essential:  The who clause distinguishes which specific neighbor; it’s essential to the meaning of the sentence.  No comma.)

Daffy signed the contract, which the client mailed overnight. (Nonessential: The which clause just adds information about the contract but doesn’t distinguish this contract from another.   Comma to set it off.)

Daffy signed the contract that contained the $200,000 bonus clause. (Essential:  The that clause tells which specific contract she signed.   No commas to set it off.)

According to this proposal, which I’ve not seen until this morning, we have 30 days to make the decision. (Nonessential:  The which” clause just adds extra information about the proposal.   Commas to set it off.)

Here’s a rule of thumb for those essential and nonessential clauses that involve that and which:

That clauses provide essential information.  Don’t use a comma.

Which clauses give nonessential information. Use commas to set them off.

Now you can sleep tonight.  No more bad dreams about commas curtailing your career or sending you to the clinker!