A sentence is usually made negative in Italian by placing the word non in front of the verb:
Francesca voule dormire. (Francesca wants to sleep.)
Francesca non voule dormire. (Francesca doesnt want to sleep.)
Loro parlano cinese. (They speak Chinese.)
Loro non parlano cinese. (They dont speak Chinese.)
Only object pronouns may be placed between non and the verb:
Lo conosciamo. (We know him.)
Non lo conosciamo. (We dont know him.)
Lo hanno fatto. (They did it.)
Non lo hanno fatto. (They did not do it.)