Non-native speaker here. I have the sentence:

  • ... where both mean and variance are normalized.

Or should it be:

  • ... where both mean and variance is normalized.

I'm not sure which is right here. Thanks for your help.

  • When you use "both A and B" you have a plural subject. Would you say "cats is" or "cats are" to make sense?
    – Davo
    May 18, 2017 at 12:18
  • 1
    @Davo it's not as cut and dried. Both variants look fine to me. They are simply ellipses of entirely different parse trees.
    – RegDwigнt
    May 18, 2017 at 12:49
  • @RegDwigнt please point me in the right direction.
    – Davo
    May 18, 2017 at 12:52
  • 2
    @Davo sure. Your verdict is alright, but your reasoning is not. It is circular in nature. You say Lars must use the plural verb because the subject is plural. Well, duh, he already knows that. That's not what he's asking. He is asking if the subject is plural. You say that it is, but that's just a claim, not evidence.
    – RegDwigнt
    May 18, 2017 at 13:06
  • @larspars, when the subject is clearly plural, why do you still be dubious about the number of the verb? May 18, 2017 at 13:54

1 Answer 1


"where both mean and variance are normalized"

If you say that two things are normalized, you could say that they are (3rd person plural) normalized.

If you are using "mean and variance" as a single item, then you wouldn't use the word "both," which indicates that they are plural. If you remove the word "both," and add the word "the," then you could feasibly have:

The mean and variance is normalized.

Source: http://www.quickanddirtytips.com/education/grammar/compound-subjects

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