A language's grammar exists to govern the expression of meaning when words are together. There are multitudes of ways for this to arise naturally, though there are most basic points. The grammatical number is one of them and is a method for languages handling plurals. There are languages without plurals, meaning that they don't possess grammatical number at all. Those languages mostly make use of context to infer plurality or specify with numbers and adjectives.
English's grammatical number is singular and plural, which we're all familiar with. There are languages that go further than that. The plural marker of a language, if there is one, normally originates from a language's word for many, all, or other quantifying adjectives. Other languages make use of reduplication, indicating more than one of something by repeating some or all of the word for that something.
Singulars and plurals aren't the only forms. There are languages making use of dual markers, specifying exactly two of something. Such a marker evolves from the word for the number two. Trials are for three of something, and quadrals are for four of something. Paucal markers are for a small number of something, with lesser paucals and greater paucals also existing. Greater plurals are for very large amounts of something, and collectives are for all of something. For this tutorial conlang, I'll go for singular, plural, and collective.
Since we're going for the proto-lang being analytical, or isolating, I asked experts on Discord about markings, and one expert, who is basically there most of the time, said this:
"You have all the same options for marking them as you do for any other category of number. And you can choose to use the exact same method for collective that you're using for plural, or you could use a different method.
* If you're going for analytic, one less-obvious option is to just make the number an inherent part of the root for nouns where it matters and just don't have grammaticalized number marking for other nouns. Maybe "rock", "handful of rocks", and "pile of rocks" are all completely separate and unrelated words. But "dog", "a few dogs", and "pack of dogs" are all the same word, and you can number or otherwise quantify them if it's really necessary but not clear from context.
* 'Completely analytic' also doesn't preclude clitics, as long as they're clearly not affixes. Maybe the number marking is like the English possessive marker and attaches to the edge of the noun phrase, regardless of whether there's a noun there, like "the cat that walks quietly's paws".
* And even if clitics are just too affix-like for your tastes, you can still have words that are part of a noun or verb phrase. You could have dedicated plural-marking words near the nouns, or plural marking built into articles and/or determiners or into noun classifiers. Or you could have number agreement markers that go near the verb. Or if you have auxiliaries (which I suspect you do, if you want highly-analytic), the agreement markers could go near them. (Agreement could indicate the number of just subject, or could indicate subject and object, or you could have one kind of marking for subject and some completely different system for object.)"
To mark plurals, we might pull a stunt Biblaridion pulled with marking them using an adjective that means the English adjective "many", or any one of its synonyms, but should we create words for those synonyms as well? Maybe not. Could make it too complex. As for collective, we could mark them with a term that means "group", or any one of that word's synonyms, though, in English, the word "group" is either a noun or a verb depending on context.
Grammatical gender is also a thing, though they don't actually have anything to do with genders or sexualities as English knows them. Common divisions of grammatical gender include masculine vs feminine and masculine vs feminine vs neuter. Other methods include animate vs inanimate, rational vs irrational, and common vs neuter(formerly the masculine vs feminine vs neuter system prior to the masculine and feminine genders merging).
