This means "by, at", but do not fall into the trap of using it to mean "in" like we would in English. I'm at a party must be translated to I'm in a party.

This is the "static position" member of the triad.

Compare to:

	Ágihoz megyek. I am going to(wards) Agi.
	Áginál vagyok. I am at/by (the house of, or stood by) Ági.
	Ágitól jöttem. I came from (the house of, or being next to) Ági.

Application of this case implies that an object is solid and that you are not (going towards/coming from) inside it.

One important thing to note is that one cannot be "inside" members of the solids group. This means that if you say Bulinál vagyok I am by/at the party, it means yo are stood next to the party, i.e. you are outside the building. You are not in the party.
Buliban vagyok I am in the party, this means you're a guest and are inside the house.

This is used for "at the house of next to, adjacent to".

• Áginál vagyok most. I'm at Ági ('s house) now.
• Kinél lesz a buli? Nálatok? At who (whose house) will the party be? At yours? (pl?)

We use the nál- pronouns, especially nálunk, to convey round our way.

• Angliában, adunk ájándékokat szülestésnapra. Nálunk is. (To a Hungarian:) In England, we give gifts for birthdays. At us too (i.e. we in Hungary do too).
• Nálunk mindig friss a kenyér, uram. At ours (i.e. in this shop) the bread is always fresh, sir.

This case is used to mean on in the context of about your person.

• Van gyuffa nálad? Do you have a match on you?
• Kinél van a könyv? Áginál? Who has on them the book? Does Ági?
• Sajnos nincs nálam elég pénz. Unfortunately, I don't have enough money on me.

The final meaning of this case is THAN in comparisons.

• Ági okosabb nálam. Ági is smarter than I.
• Ági nem magasabb nálad. Ági is not taller than you.
• Ő nem szebb Áginál She is not prettier than Ági.

The case is explained in more detail here: Comparative adjectives and equality of adjectives.