Lompakko on takin taskussa.

to be

Breakdown of Lompakko on takin taskussa.

• -ssa: in
• tasku: pocket
• takki: coat

Questions & Answers about Lompakko on takin taskussa.

Why is it on and not ovat or something else?

On is the 3rd person singular form of the verb olla (to be). The subject lompakko (wallet) is singular, so you use on.
Plural would be Lompakot ovat ... (The wallets are ...).

What case is takin, and what does it do here?

Takin is genitive singular of takki (coat). The genitive often marks possession or “belonging to”:
takin tasku = the coat’s pocket / a pocket of the coat.
So takin taskussa literally means in the coat’s pocket.

What case is taskussa, and why is it used?

Taskussa is inessive singular of tasku (pocket). The inessive case ending -ssa/-ssä means in (inside something).
So taskussa = in the pocket.

Why is the ending -ssa (not -ssä)?