Have I the skill to be friendly? (7)
I believe the answer is:
amiable
'friendly?' is the definition.
(similar in meaning)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for amiable that I've seen before include "'Cordial, friendly (7)'" , "Good-humoured" , "Friendly, kindly" , "Of sweet and friendly disposition" , "'Affable, genial (7)'" .)