Learnt, perhaps, what the charge for hiring is (6)
I believe the answer is:
rental
'the charge for hiring is' is the definition.
I can't tell whether this defines the answer.
'learnt perhaps' is the wordplay.
'perhaps' indicates an anagram.
'learnt' anagrammed gives 'RENTAL'.
'what' acts as a link.
Can you help me to learn more?
(Other definitions for rental that I've seen before include "Tenant's payment" , "To do with a letting" , "Hire charge" , "Amount paid for hire" , "Money paid for hire" .)