This is the 52nd most frequent Turkish word.
yok
"Yok" means "not there," "absent," or "no" in English.
In this sentence, 'yok' indicates the absence of something and corresponds to 'there is no' in English.
Kitap yok.
There is no book.
Here, 'yok' expresses the non-presence of a person at a specific location or state, equivalent to 'is not' in English when negating presence.
Ahmet bugün evde yok.
Ahmet is not at home today.
In this usage, 'yok' conveys the absence of an issue or problem, used idiomatically to mean 'no problem' or 'it's fine'.