Thx for the reply, but I still don't get this sentence. The suffix on 'agy' is 'a' which is third person singular, and 'onok' is third person plural, if I'm getting this right. How come?
Because after possessive pronoun " önök " you don't have to put the subject " ágy " in plural. A few examples.
Which is your house? - Melyik az önök háza ?
Which is your car? - Melyik az önök kocsija?
The actual rule is this:
For the third person plural, you put "-k" on the possessed only if:
- the possessor is not mentioned:
"az ágyuk" - (their) bed
- or if the possessor is the personal pronoun itself. In which case, the pronoun loses the "-k" ending. So, it will be "ő", instead of "ők":
"az ő ágyuk" - their bed
In all other cases, you use the possessed as in the singular:
"a gyerekek ágya" - the children's bed