"The young boys are short."

Translation: A fiatal fiúk alacsonyak.

[Yiffniff]

Why do we add the plural suffix to alacsony but not to fiatal?

[mizinamo]

No endings on adjectives that are before nouns (like "fiatal" in this sentence).

Linguistically speaking: predicative adjectives inflect but attributive adjectives do not.

[Yiffniff]

Oh, that makes sense, thank you!

[96314081311257]

This is just how it's done. Fiatal fiúk means young boys, in which case fiatal is not pluralized. Alacsonyak means "they are short" here, in which case you do pluralize.

[Yiffniff]

Thanks!