juvelry is exactly right.......but sometimes the other form could be used in a conversation as an answer to a question. It really depends on the context and what came before. eg: 2 people talking about their body weight.
A: You aren �t very heavy are you?
B:No. I never have been. (very heavy is implied, but could be spoken) - the emphasis is on NEVER.
BUT if B replied
B: No. I �ve never been very heavy. (very heavy would have to be spoken and then the above rule is followed)
You would always be correct if you used the rule.
Rules are made to be broken.
(Especially in the English language

)