"There is a boy."
Translation:Il y a un garçon.
The literal translation of il y a is 'it has there'. But the closest phrase in English to the meaning is 'there is' or 'there are'. It's one of those packages that is used a lot, so understand that it doesn't translate well on a 'word for word' level, learn the meaning, and keep on going. http://french.about.com/od/vocabulary/a/ilya.htm
No. If you wanted to say 'A boy is there' then you would use 'Un garçon est là' but 'There is' at the beginning of a sentence is a package that is represented by 'Il y a' It's not a word for word translation but that is what French people use when they want to say 'There is'
It does, and it doesn't. It means it in the sense where you might remark to someone 'There is my brother! I haven't seen him for ages!' It's used to bring attention to something or someone's presence and sometimes to indicate that something is there for you.
The far more common translation for 'There is' is 'Il y a' when used as a statement.
I mean that 'Here you are is a boy' (or possibly 'here is is a boy') is the literal translation of 'Voilà est un garçon'
Voilà un garçon = Here is a boy (presenting a boy to you)
Il y a un garçon = There is a boy (talking about a boy) which is what this phrase is. "Il y a" is a set phrase meaning 'there is' or 'there are' (depending).
Perhaps read the other comments first? Voilà and Voici are used when you are presenting or placing something (or possibly someone) to someone. A sort of 'here you are' or 'there it is' in gist form. For 'There is an X' construction indicating that something exists the idiom that is used is 'Il y a', don't worry about direct transliteration, just memorise the phrase.
Because, although in English the word 'there' to indicate the place and the word 'there' to indicate the existence of something in there is, are the same word, but they are not in French. In French there is a package, which is always used to represent 'there is' and that is 'Il y a'. (of which the y is the 'there' part)
Là est un garçon would mean That place is a boy, which makes no sense at all.