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An expression below embarrasses me. Why not "it's" but "their" litter?

a cat can use their litter box.

in the context we are talking about a few cats, but in this, specific, example we speak about one cat.

marked as duplicate by Janus Bahs Jacquet, sumelic, AmE speaker, tchrist Feb 15 '18 at 1:23

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  • It’s = it is/it has. Its = belonging to ‘it’. And in your example, its would be more common, unless it’s using a litter box that belongs to several other cats. You can also search for ‘singular they’ on here, and you’ll find hundreds of questions that deal with this. The closest is probably this one, of which this is essentially a duplicate. – Janus Bahs Jacquet Feb 14 '18 at 23:32

"their" is a gender neutral term that gets used (for singular or plural alike) when the gender is uncertain but the subject does have a gender attribute. "its" gets used when the subject does not.

"It" when used to refer to a child or animal is often taken as denigrating.

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