External possession, also know as the genitive caseis when we're talking about an object being owned by a named owner, but then the object is not necessarily named. For example, when we have already mentioned my book, and you want to then talk of Ági's book, one can imply the owned object thus: "My book is here. Where is Ági's?" We do not need to mention the book a second time.

The characteristic ending for indicating external possession is -é.

The question whose? is then easily made:

• ki? who?
• kié? whose?

See also the section on Hungarian possession.

1. The genitive may stand on its own.
   • kié ez a könyv? Ágié whose is this book? Ági's
2. The genitive may stand for its own possessive to save repeating it.
   • ez a kalap Ágié this hat is Ági's
   • is rather a short version of
   • ez a kalap Ági kalapja this hat is Ági's hat
3. The genitive make take endings just like any other possessive noun. It make not take a second genitive, nor can it be applied to plurals (see below). Otheriwse it can take the usual noun cases
   • még nem találtad meg Ágiét? have you not yet found Ági's?

The genitive can't be applied to plurals, rather you have to strip a noun of its plural and then add the plural version of the genitive to the root.  It's quite rare to use this structure though.

Just like with explicit possession of multiple objects, we have -éi to represent the external possesion of multiple objects.

• ki? who?
• kiéi? whose (pl.)?
• kiéi ezek a könyvek? whose are these books?
• ezek a könyvek Ágiéi these books are Ági's
• még nem találtad Ágiéit? have you not yet found Ági's?

Here is another example, sent in by reader Gábor Bánóczi. It shows the construction of the word fiaiéi those of my sons, i.e. my sons'

• fia his son
• fiai his/her sons
• fiaié his sons' (object)
• For example, a bárány a fiaié the lamb is her sons', or, the lamb belongs to her sons.
• fiaiéi his sons' (objects)
• For example, a bárányok a fiaiéi the lambs are her sons', or, the lambs belong to her sons

In English, "who's" means "who is," or "who has." It's nothing to do with possession.