Could you tell me please if these sentences are right?
I have two years experience.
I have a two years experience?
I have a two year experience.
a two year(s) experience is necessary.
two years of experience is needed.
two years experience is neded.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.