If you want to say that an action did not happen, you have to use the prefix ne. Since it's a prefix, you have to attach it to the beginning of a verb.

neduoti - not to give
nekalbėti - not to speak, not to talk
negyventi - not to live

aš neduodu (I don't give)
tu neduodi (you don't give)
jis, ji, jie, jos neduoda (he, she, they don't give)
mes neduodame (we don't give)
jūs neduodate (you don't give)

aš nekalbu (I don't speak)
tu nekalbi (you don't speak)
jis, ji, jie, jos nekalba (he, she, they don't speak)
mes nekalbame (we don't speak)
jūs nekalbate (you don't speak)

aš negyvenu (I don't live)
tu negyveni (you live)
jis, ji, jie, jos negyvena (he, she, they don't live)
mes negyvename (we don't live)
jūs negyvenate (you don't live)