The term in linguistics for a category of 3 or 4 things is "paucal". Most languages with a paucal separate 2 from 3 or 4, resulting in four noun categories/forms by number: singular (1), dual (2), paucal (3 - 4? a few?) and plural (5+). That's quite a common pattern among the world's languages. Polish and the other Slavic languages with this feature are a little unusual in not having the separate dual. A few languages have a trial (3) as a distinct category but it's rare. And some languages distinguish between a greater and lesser paucal, roughly "a few" vs "many", usually with the singular, dual and plural as well, having 5 categories of noun number.
Languages with these features often have lots of irregularities around them, too. In the same way that "pants" are plural for no reason in English, eyes might be plural instead of the obvious-seeming dual, etc. And if that seems all a bit unnecessarily numerical, you may be right; Chinese has gotten by for thousands of years without any plurals at all.
Counting words and 们 aren't the same, as they aren't declensions. You add on the syllable rather than actually changing the syllable of the noun itself.
Granted, that's still different from saying that Mandarin doesn't have a concept of plural, but I think the underlying point- no conjugation or declension- is very different from the other languages being discussed.
To be more accurate, 们 isn't a plural marker more because of the fact that it's not productive[1], rather than the fact that Chinese doesn't have declension. If 们 were able to be suffixed to any noun to make it plural, then you could consider it to be a plural marker, even though the noun isn't technically declined. That's not the case anyway though, since 们 can only be used with a closed set of pronouns or in a limited way to refer to groups represented by the noun its attached to (in this sense it's more of a metonymic[2] marker rather than a plural marker). For example, 白宮们 can be used to translate "the White House" when it refers to the President and his administration, and cannot be used to mean "white houses".
It is productive. It can't pluralize anything, but it can pluralize anything that refers to people and it is actively used in novel ways. I've seen someone refer to 美国的妈妈们; metonymy is not involved there. It just means "American mothers", as distinct from a hypothetical 美国的妈妈 "America's mother".
However, the other angle on this is that Mandarin pronouns have singular and plural forms (plurals using 们), and the use of the correct form is obligatory, which suffices to show that plurality exists in the language. Although it isn't the case that 们 is unproductive, even if it was unproductive that still wouldn't show that the language has no plurals.
> in this sense it's more of a metonymic marker rather than a plural marker). For example, 白宮们 can be used to translate "the White House" when it refers to the President and his administration, and cannot be used to mean "white houses"
I should note that this argument doesn't entirely hang together. You can make "the White House" explicitly plural in English by giving it a plural verb:
When the comment you replied to mentioned "Chinese has gotten by for thousands of years without any plurals at all", I understood it to mean that Chinese has not featured any general system of marking plural by grammatical means[1], which is what is usually understood by the term "plural"[2], not that Chinese has no ability to express a more-than-one count distinction at all (which isn't the case in any language as far as I'm aware).
> It can't pluralize anything, but it can pluralize anything that refers to people and it is actively used in novel ways. I've seen someone refer to 美国的妈妈们; metonymy is not involved there.
It is productive in a limited sense in that way, but not as a general plural marker as you're arguing, and it's limited because 美国的妈妈们 means "American mothers" in that it necessarily refers to them as a collective group (which I argue is an instance of metonymy) rather than a set of more than one "American mother". For instance you cannot say *三个美国的妈妈们 to mean "three American mothers"; you must instead say 三个美国的妈妈 because 美国的妈妈们 can only ever refer to the entire collective group.
> I should note that this argument doesn't entirely hang together. You can make "the White House" explicitly plural in English by giving it a plural verb
This is a feature of UK English where collective nouns agree with plural forms of verbs. US English on the other hand, requires the singular form[3][4]. This has no bearing on how we analyze Chinese.
Languages with these features often have lots of irregularities around them, too. In the same way that "pants" are plural for no reason in English, eyes might be plural instead of the obvious-seeming dual, etc. And if that seems all a bit unnecessarily numerical, you may be right; Chinese has gotten by for thousands of years without any plurals at all.