"My mom loves dogs but not cats." "My mom loves dogs and cats."

Why or why not should I use a comma in these sentences?

  • 3
    What do you think?
    – WS2
    Oct 15, 2016 at 17:48
  • 1
    Possible duplicate of Using a comma before "but"
    – Silenus
    Oct 16, 2016 at 0:11
  • I am really sorry, but I am not a native speaker. If I know, why do I even bother to ask? Please pardon my English.
    – laishiekai
    Oct 16, 2016 at 4:18

2 Answers 2


"My mum loves dogs, but not cats" this can work since it's two distinct objects or animals in this case. It's not absolutely required though.

"My mum loves dogs and cats" doesn't need a comma, since there is no reason to split different objects or points.


Neither sentence needs a comma, but for different reasons.

In My mom loves dogs but not cats. the sentence from "but" on is basically a negated direct object of what Mom loves (what Mom doesn't love). Compare with, My Mom loves dogs, but she is scared to death of cats. Now the comma is required because you have joined two independent clauses together. If "she" is absent from the subordinate clause, some accepted styles would leave off the comma, because it would separate the "is" from its subject. The Chicago Manual of Style, however, uses the comma.

In My mom loves dogs and cats. you have formed a two-item list. As such, the word "and" is the only divider needed. In a longer list (more than two), commas become necessary:

  • My Mom loves dogs, cats, hamsters, and parakeets.

The final "," before "and" is optional and called the Oxford comma. To me, it adds clarity and consistency. In some complex lists, the comma before "and" is actually necessary to parse the sentence correctly. If it is necessary some of the time, why not use it all of the time?

  • This is a good answer, but if you'll forgive some pedantry, I'd like to see you sharpen it. First of all, how do you square your answer with the comma in your first sentence? There is no subordinate clause "from 'but' on" in the first italicized example, just a compound direct object. "Joined two sentences together" is better as Joined two independent clauses together. This isn't a matter of "formal English" or "required" typography; only adherence to style guides. I don't know which one you use. I prefer the Chicago Manual of Style, which agrees with your recommendations. [con't]->
    – deadrat
    Oct 15, 2016 at 18:34
  • <-[con't] I would leave out personal recommendations, as they're hard to cite. There's an argument to be made for the comma in My mom loves dogs, but is scared of cats, but not on the grounds of emphasis. It avoids the garden path of My mom loves dogs but grudgingly. The comma before and in an extended list is called the Oxford comma, and I don't think it's controversial. There are just two styles, with comma and without. Finally, you don't need the period after cats in your second line.
    – deadrat
    Oct 15, 2016 at 18:44
  • ' I personally might throw in the comma anyway, to emphasize the contrast.' Me too. Hello, Rich. I agree that this is a good answer (with deadrat's caveat), but these issues have been covered on ELU before. Oct 15, 2016 at 19:49
  • 1
    deadrat, thank you. I incorporated most of your input. It did not feel pedantic at all, but simply a logical explanation of how my answer could be improved. You may have noticed I left the first sentence alone, with a comma before "but". My reason is ear. If I say the sentence aloud, it sounds more clear to me with a pause at that spot. Without the pause, it sounds sort of like a wall of sound, similar to the wall of text one sees when someone writes without spacing paragraphs. I hope you were merely challenging me to think about it, instead of declaring it incorrect. If so, it worked!
    – RichF
    Oct 15, 2016 at 23:37
  • If you care to see the original for comparison purposes, I saved it. see r0k.us/rock/junk/originalComma.png
    – RichF
    Oct 15, 2016 at 23:39

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