When saying must not in french?

On ne doit pas fumer parce que..

negation :

ne + verb + pas

ex. Je ne pars pas - I don't leave

je ne dors pas - I don't sleep

je ne parle pas - I don't speak

je ne sais pas - I don't know

Salut

@kaelindra : Juste, j'ai modifié le 'on' et je ne me suis pas relue. Merci

On ne doit pas fume parce que...

On ne doit pas fumer parce que ...

In France you often see 'Defense de fumer' - smoking not allowed.

On ne doit pas fumer (note that an infinitive is needed here)

On ne doit pas fume parce que

Passion piink xx

same as before.....on ne doit pas fumer

Well that would be a shabby american translation all around.

But it's

"On ne doit pas fumer parce-que"

Which mean "You don't need to smoke because"

It sounds silly.

Depending on the context.

"Ne fumez pas"

"C'est interdit de fumer ici"

"Il faut quitter les cigarettes"

"Il faut laissez tomber"

Please Ginam pay attention to your writing, there are many mistakes in it !

It's not "je ne part pas" but "je ne parS pas".

And it's not "je ne dort pas" but "je ne dorS pas".

The answer to your question is, as everyone said, "on ne doit pas fumer parce que..."

pas fumer