The Misunderstood Comma

two students studying

Comma use falls into two categories:  (1) too much, and (2) too little.

In the “too much” category we have errors when students place a comma in front of an integrated phrase:

[Between a subject and predicate:] His brilliant mind and curiosity, have left.

[Between the verb and its compliment:] He mentions, that not knowing how to bring someone back can be a deadly problem.

 [Between a noun and an integrated relative clause:] The ethnocentric view, that many Americans have, leads to much conflict in the world.

[Between a subordinator and its clause:] There was a woman taking care of her husband because, an accident left him unable to work.

[Between a definite generic noun and the name identifying its referent (neither comma is correct here):] I went to see the movie, “Midnight in Paris” with my friend, Jessie.

And in the “too little” category, students forget to insert a comma to set off a supplementary word or phrase:

[Surrounding a sentence adverb:] In many ways however life in a small town is much more pleasant.

[Between a preposed adjunct and the main clause:] Using a scooping motion toss it in the air.

[Before a result adjunct:] The molecule has one double bond between carbons generating monounsaturated fat.

[Before a contrast adjunct:] Their religion is all for equal rights yet they have no freedom.

[Before a supplementary relative clause:] There are monounsaturated fatty acids which lack two hydrogen atoms.

[Before a direct quotation:] She said “I don’t want to go home.”

Source:  Steven Pinker’s The Sense of Style