Inessive / Seesütlev

The Inessive/Seesütlev is almost the same as "in" or "at" in english

Add an s to the genitive form

[in whom?]	[in what?]	[where?]
kelles?	milles?	kus?

The following four nouns are declined in the Genitive/Omastav case:

Book	Room	Bridge	Boat
raamatus	toas	sillas	paadis

Milles on kohv?	[where is the coffee?]
Kelles oled sa kindel?	[in whom are you sure?]
Kus sa oled?	[where are you?]