Sentences 2 and 4 are right.
In this context, I think that 'de' is only used in a negation.
Je ne vois pas de lapins.
Note: A negation is not with 'de' when you use the verb 'être'. Then it's just
Je ne suis pas un lapin.
Sentences 2 and 4 are right.
In this context, I think that 'de' is only used in a negation.
Je ne vois pas de lapins.
Note: A negation is not with 'de' when you use the verb 'être'. Then it's just
Je ne suis pas un lapin.