Negation and questions: nuk, s', mos, a
"Not" before a verb is nuk or, in speech, s': Nuk kuptoj — "I don't understand". Prohibitions use mos: Mos fol! — "Don't speak!". A yes/no question can start with a: A flet shqip? — "Do you speak Albanian?".
Nuk and s'
Nuk goes right before the verb or before a short form: Nuk punoj sot — "I'm not working today", Nuk e di — "I don't know". S' means the same, is attached with an apostrophe and is more common in speech: S'kam kohë — "I have no time", S'ka problem — "No problem".
Mos — "don't"
Mos is used in prohibitions and requests: Mos fol shpejt! — "Don't speak fast!", Mos u shqetëso! — "Don't worry!". It also comes after të: Më mirë të mos shkojmë — "We'd better not go".
Nobody, nothing, never
Albanian uses double negation: Nuk kam asgjë — "I have nothing" (literally "I don't have nothing"), Nuk shoh askënd — "I don't see anyone", Nuk pi kurrë kafe — "I never drink coffee".
Questions: a, po, jo
A yes/no question is asked with intonation or starts with a: A ke kohë? — "Do you have time?". With a the question is clearer, especially in writing. The answer is po "yes" or jo "no". "Isn't it?" is apo jo?: Kjo çantë është e shtrenjtë, apo jo? — "This bag is expensive, isn't it?".