In English we express the negative by saying "don’t" or "not", e.g. "I don’t work hard" or "She is not listening".
The basic negative form in French is obtained by placing "ne" before the verb, and "pas" after it.
i.e. Je ne travaille pas I don’t/am not working
Elle n’écoute pas She doesn’t/is not listening
In the perfect tense the same rule applies, but the "ne" and "pas" go around the part of "avoir" or "être".
i.e. Je n’ai pas travaillé I didn’t work/haven’t worked
Elle n’a pas écouté She didn’t listen/hasn’t listened
There are several other negative forms which work in the same way.
ne verb rien nothing je ne fais rien
je n’ai rien fait
ne verb jamais never il ne travaille jamais
il n’a jamais travaillé
ne verb nulle part nowhere nous n’allons nulle part
ne verb plus no more/no longer il n’y a plus de livres
ne verb que only elle n’a que deux livres
ne verb ni ..ni .. neither .. nor .. je n’aime ni les pommes ni les poires
ne verb personne nobody il n’y a personne