qué chostoso
qué chostoso
https://verbix.com/webverbix/finnish/chostata
Seems right.
Edit: Oh no! chostaavein, chostaaveine-, chostaamein, chostaameine-, chostattavein and chostattaveine- should have "i" instead of "ei."
The page also doesn't list the possessive forms of the nominal forms. For e.g. "chostattavista," there's chostattavistani, chostattavistasi, chostattavistaan, chostattavistamme and chostattavistanne.