Put no directly before the verb and nothing else changes. To answer a question negatively you often need it twice: once as the answer and once in the sentence - No, no es tarde.
Examples
- No es la una todavía.
- It isn't one o'clock yet.
- No trabajo los domingos.
- I don't work on Sundays.
- No, no hablo alemán.
- No, I don't speak German.
The mistake to avoid
Nothing may come between no and the verb - it is "no lo sé", never "lo no sé".
Where this fits in
Numbers, days, time, Spanish A1: Count, talk about days and months, give the time, and handle numbers in real situations.