Learn Turkish: Sakın geç kalma! - Mind you don't be late!

The dictionary root of the verb "to stay" is kal. To tell someone not to do something (the negative imperative), you add the negative suffix -ma or -me directly to the root. Because kal has the hard vowel 'a', vowel harmony dictates we use -ma, giving us kalma ("don't stay" or "don't be").

I thought kalmak meant "to stay". Why is it translated as "don't be late"?

You're right that kalmak means "to stay"! However, in Turkish, the standard fixed expression for "to be late" is geç kalmak (which literally translates to "to stay late"). You will use this verb combination instead of the verb "to be" whenever you talk about lateness.

What exactly does the word sakın add to the sentence?

Sakın is a special warning word used almost exclusively with negative commands. It translates to phrases like "mind you", "make sure you don't", or "don't you dare". It adds strong emphasis to the warning, making the command much stricter than just saying geç kalma.

Who is this command addressed to, and how would I say it to a group?