This is the 255th most frequent Czech word.
jestli
"Jestli" means "if" or "whether" in English.
Used to express a possibility or uncertainty.
Nevím, jestli přijde.
I don't know if he/she will come.
Used to inquire about the state or situation.
Zeptejte se, jestli tam ještě jsou.
Ask if they are still there.
Used to express a preference for certain knowledge or truth.