"He has twenty children."
Translation:Yirmi tane çocuğu var.
Would it also be correct to say: "Onun yirmi çocugu var"?
It still sounds a bit odd to me to add "tane" for living beings :D I'll get used to it, though. Are there other words like "tane" for counting special types of things? (Like litre, metre, ... but more abstract, that is, what linguists call quantifiers?)
Yes, it would be correct.
And no, there are no other "quantifier" words like in Japanese or Chinese.
Touché. :D Okay, there's that too. But "adet" is not used with people, methinks. It's unnatural to say: "benim üç adet kardeşim var," whereas "tane" works just fine. I guess "X adet" is more like "X pieces of".
I'm struggling to see how this means "he has twenty children" as opposed to "there are twenty children."
The possessive suffix -u on çocuğu makes it "his child(ren)", and possessive suffix + exist is used for "have".
Yirmi tane çocuk var: there are twenty children
Yirmi tane çocuğu var: he has twenty children
How does one know the difference of when to use var, and when to use the locative?
As I understand it: use var with indefinite possession (elması var "he has an apple) and locative with definite possession (elma onda "he has the apple").
No; it's not the accusative case but the possessive ending for "his" -- to express "he has children" as "his children exist" or something like that.
For nouns that end in a consonant, the two look the same, but you can see the difference in nouns that end in a vowel. For example, "he has an apple" is Elması var with the possessive ending -sı, and not *Elmayı var with the accusative ending -yı.
Like onun çocuğu, yes. Something like "his children exist" or "his children are". (var is not "to have" but more like "there is", as in Orada bir hastane var "There is a hospital there".)
I think that would be "He has the twenty children".