Bonjour,
Réponse :
1) Jane plays the piano very well
Jane doesn't play the piano very well.
2) We work very hard.
We don't work very hard.
3) He has a bath every day.
He doesn't have a bath every day.
4) You do the same thing every day
You don't do the same thing every day.
Explications :
forme négative,
don't / doesn't + base verbale ( c'est l'infinitif sans "to" )
la marque de la 3ème personne du singulier est dans l'auxiliaire ( doesn't )