to attempt, to test, to try, to sample
Building blocks
katse- experiment
-ta- causative (“make something be X”)
-ma - infinitive ending
It’s related to another Estonian verb, katsuma (to touch, to try).
Katsuma itself is likely derived from Proto-Finnic: kaccodak
How to use it
What you are experimenting/testing is in the Partitive case (third base form).
Examples
Ma katsetasin uut retsepti
Literally: “I experimented new recipe”
Idiomatically: “I experimented with a new recipe”
Ma - Pronoun - Nom Sg, "I"
katsetasin - Verb - 1P Past Sg, "experimented"
uut - Adjective - Part Sg, "new"
retsepti - Noun - Part Sg, "recipe"
Poisid katsetavad oma leiutist
Literally: “Boys experiment their invention”
Idiomatically: “The boys are experimenting with their invention”
Poisid - Noun - Gen Pl, "Boys"
katsetavad - Verb - 3P Present Pl, "experiment"
oma - Pronoun - Gen Sg, "their"
leiutist - Noun - Part Sg, "invention"