whenever · conjunction /wenˈev.ər/Full view
B1 every time or any time
Dictionary example:

Whenever I go there they seem to be out.

Learner example:

I read whenever I can, specially at night. (Preliminary English Test; B1; Italian)

whenever possible
B2 every time it is possible
Dictionary example:

I try to use olive oil whenever possible.

Learner example:

My friends have always regarded me as a cheerful, active girl, who is glad to help out whenever possible. (First Certificate in English; B2; Chinese)

whenever · adverb /wenˈev.ər/
C2 every time or any time
Dictionary examples:

"Will it be okay if I do it tomorrow?" "Sure, whenever."

Do it in a spare moment at the weekend or whenever - it really doesn't matter.

Cambridge University Press