"The book that is next to the new television is long."
Translation:Az a könyv hosszú, amelyik az új televízió mellett van.
I don't get the difference between ami, amely and amelyik ; they all seem to be relative pronouns meaning "which" used in similar situations. It seems we need a good lesson on these ; there are lots of questions and the reference doesn't explain much beyond some basic examples that are not enough to derive the rules.
Teaching grammar has always been one of the weaknesses of Duolingo's approach.
Some teams manage to get basics down in the "tips and notes" for lessons (which not everyone reads, especially once the course is available on mobile apps which don't even show them), but it's always best to supplement your Duolingoing with external grammar references.
Yep, I've got my grammar book nearby "Gyarkolo magyar nyelvtan" ; it's been recommended to me by a native here in Hungary, and it's really good ! I'm just surprised such a complex subject, relative pronouns, is introduced here with so little background. But hey, still better than nothing :D So, not complaining.
It is not correct but it is widely used like that. Does that answer your question? :)
Compare these sentences:
I want the one that you want. - Azt akarom, amelyiket te (akarod).
I want what you want - Azt akarom, amit te.
So it is closer to "what" in this context.
I went to school, which was a good idea. - Elmentem iskolába, ami jó ötlet volt.
In the place of "which".
So these are the correct ways of using "ami".
But you wouldn't say "That book is long, which is next to the new television" in English. You'd say "The book that is next to the new television is long." The translation is correct. (There may also be other correct translations.)
Sentences are structured somewhat differently in Hungarian. I rather enjoy it -- I find myself also structuring my thoughts somewhat differently.
In English, "The book which is...." (or "The book that is ...") is considered enough to determine which book it is, so we don't usually use "that".
But Hungarian grammar is different; they say the equivalent of "That book ..., which ...".
Note also that English puts the qualifier immediately after the book while Hungarian does not; this may explain the preference of the two languages for their respective solutions. (Since the qualifier comes a bit later in Hungarian, it can be a good "flag" to put az "that" next to the noun to signal to the listener that this is a particular book.)