"Most of them are there."
Translation:Tá a bhformhór ann.
ann = "There/in existence", to understand this, in English Irish people will often say "Ah there you are". This actually means "You're alive, you're still with us, I havent seen you in an age, You still exist", it does not mean "you are standing in that specific spot infront of me". (ann not ansin).
Ansin = "There/in that place", So for example if you were directing them in a room, lets just say for argument sake they were blindfolded and you were playing a game, and you were trying to direct them to a specific spot in the room, and you would say "back a bit, left a bit, you're there" (ansin not ann).
The problem you might encounter is Irish uses "ann" in a lot of ways that it isnt or is dropped in English, so you default to the "in that place" definition in your head and it can catch you out. The examples from teanglann are good.. "
Tá Dia ann, God is there/exists.
Tá an saol ann, the world exists.
Tá lá maith ann, it is a good day.
Tá an uair ann, the time has come. Nuair a bhí m’athair ann, when my father was alive.
So, "most of them are there" will use ann because you have to think of it being used in a sentence like "I'm going to make this jigsaw, do you know if it has all the bits?", "Most of them are there/exist", this kind of situation would be "common" compared to the situation where ansin might be used. I'm not saying ansin could never be used, but it would probably be a more specific conversation. In English the english setnence almost makes you see a person standing atop a hill pointing down at a group of people saying "most of them are directly there in that exact position", in Irish ann would probably still be used, although if you were pointing at a spot on a map ansin might be used.
Anyway its good they use ann as its more correct, and not accepting ansin lets people find out the difference between ann and ansin.
My understanding, and the way I've had it explained to me is that "ann" is, technically, a contraction of "i" and "ansin/anseo" and, so, you would need to use it because you would need the preposition in this formulation (due to the fact that it is more "there exists X here")... i am, however, completely prepared to be corrected.