"The garage is next to the house."

Translation: A garázs a ház mellett van.

[SedatKlc]

can we say 'A garázs a háznál van'?

[vvsey]

You can but it sounds a bit unusual.

[DrJake2]

looking at this particular response, i'll urge you to explore it from the native english speaker's point of view. In english... 'next to' or 'by' are 100% fungible. A garage may comfortably (and not unusually) be described as being next to or by the house. Nem baj. To make the comment that it sounds unusual ignores the problem in translation, and the resultant stiffness of the right/wrong response the learner must deal with.
Also, if this sounds unusual, i urge you to read through the other examples in the lesson and vet out any others where the adessive and the preposition are unusually applied. Because there does not seem to be a rule yet.

[fekundulo]

should be accepted.

[javra]

Why is "a ház mellet a garázs van" not possible?

[Mio994903]

A ház mellett a garázs van.Possible too?

[RMattlage]

Why isn't the "van" optional? i.e. is "A garázs a ház mellett" also correct.

[mizinamo]

It's not optional when you use an adverb (János jól van) or describe where something is (as here).

[JeanMencze]

I must be mixed up because I thought "van" wasn't used when talking about where something is located.