Ever is used in questions emphasize the idea that something has been done for the first time or at least once in a person’s lifetime:

Have you ever climbed Mount Everest?	Has he ever given a piano recital?

Negative statements with ever:

I haven’t ever climbed Mount Everest.

He hasn’t ever given a piano recital.

Note that these are negative statements because the verbs are in negative form (haven’t / hasn’t).

Negative statements with never:

I have never climbed Mount Everest.

He has never given a piano recital.

Note: there are no double negatives in English [hasn’t never = NO, NO, NO!!!],            therefore when you use never the verb is in affirmative (have/has).