• Use the Oxford comma: commas between items in a list, including before the “and”. Use it because it makes it extra clear that the two last items in the list are separate. “Apples, oranges, and pears” clearly means three kinds of fruit. “Apples, oranges and pears” implies two sets of fruit: apples, and oranges and pears. See the difference? Of course, this only really matters if you’re writing a legal contract about shipments from two different orchards, but I like the clarity the Oxford comma creates anyhow.
• You can combine complete, related sentences into one if you use a conjunction (for, and, nor, but, or, yet, and so—FANBOYS). So, these three sentences:
“They saw a funnel drop out of the clouds.”
“It didn’t seem to be heading their way.”
“They kept on stacking the hay.”
“They saw a funnel drop out of the clouds, but it didn’t seem to be heading their way, so they kept on stacking the hay.”
That doesn’t read very well, but we can improve it by adding “since” which can be used as a conjunction (among other things—look it up):
“They saw a funnel drop out of the clouds, but since it didn’t seem to be heading their way, they kept on stacking the hay.”
Here, the double conjunction lets you kill the final conjunction—oh, forget it. Stupid harvesters.
• Use commas between multiple adjectives before a noun: “The great, big, red elephant.” You don’t need a comma between red and elephant: “The red elephant” makes perfect sense, at least grammatically, without it.
• Notice the little additional phrase, “at least grammatically”? We didn’t really need that info, but stuck it in and bracketed it with commas to show that it’s an extra bit. The basic sentence would have been fine without it, just not as clever.
• Don’t use a comma if the descriptive word before the noun is also a noun: “she brought out a platter of steaming lamb curry.” “Lamb” is part of the noun “curry”—it’s officially called an adjunct noun—so you don’t need the comma. You do need some tongue-cooling, yogurt raita to go with it.
• Oh, look, a compound adjective. Tongue-cooling. Those need to be hyphenated. Wait, that’s a different lesson. Here, you were supposed to notice the yogurt raita, which didn’t need a comma because yogurt is an adjunct noun.
• If you have one complete sentence and one incomplete sentence, combine them with a comma. It doesn’t matter much goes first.
“”The sentence was incomplete.”
“Because he got a last-minute pardon…”
“Because he got a last-minute pardon, the sentence was incomplete” is just as good as
“The sentence was incomplete, because he got a last-minute pardon.”
The whole thing might be nicer with an additional phrase that gives context:
“He dashed off a cryptic message to his escape team. The sentence was incomplete, because he got a last-minute pardon.”
This had consequences.
• Use a comma before “while” when you’re comparing two ideas.
“Speed dating is essentially honest, while online matchmaking profiles are usually fake.”
Without the comma, it sounds like they’re speed dating at the same time they’re doing eHarmony, which they probably are. Some people are desperate.
• When you use quotes, you give attribution to the source, right? Yes, you do. But do you use commas correctly when you do so? Probably not. What matters is whether the attribution comes before or after the quote.
Senator Whitewash said, “Nothing illegal was done here.”
The comma goes outside the quotation marks when the source comes first.
“Nothing illegal was done here,” Senator Whitewash said.
Here the comma follows the quote, inside the quotation marks.
But the use of passive voice indicates that illegality, was, indeed, involved.
• I can also tell you why I put all those commas in the last sentence. How would it read without them? Sometimes commas are just about creating aural rhythm. And where would we be without that?