It's a negative. You put the words on either side of a conjugated verb or in front of an infinitive. For example:
Je vais... (I go...) or,
Je ne vais pas... (I do not go...)
"je ne suis pas" means "I am not.." in French.
je ne vois pas - tu ne vois pas - il, elle ne voit pas - nous ne voyons pas - vous ne voyez pas - ils, elles ne voient pas
'to miss somebody' is resersed in French (quelqu'un me manque) vous ne me manquez pas = I don't miss you vous n'allez pas me manquer = I won't miss you je ne vous manque pas, je ne te manque pas = you don't miss me.
il n'aime pas l'hiver: he doesn't like Winter
Je ne comprends pas (I don't understand) is the correct conjugation. Comprendre is the infinitive and cannot be used as such unless there is another conjugated verb just before it: Je ne peux pas comprendre (I cannot understand) is correct, but 'je ne pas comprendre' (I not understand) is not.
Ne m'oubliez pas means 'don't forget me'.
Nicht freimachen! No stamp required! Ne pas Affranchir!
"je ne suis pas" means "I am not.." in French.
Ne reviens pas means "don't come back".
"Je ne comprends pas" means "I do not understand" in English.
"Tu ne parles pas français" means "You do not speak French" in French.
non je ne sais pas = no, I don't know
Perhaps do you mean 'maintenant ne me remerciez pas' which means 'now, don't thank me'
L'école ne me déplait pas means School / the school does not displease me.
Je ne sais pas means 'I don't know'.
Je ne parle pas français (?) - I don't speak French
"Non, je ne suis pas," means "No, I am not." in English.