Put in charge (5)
I believe the answer is:
prime
This might be a double definition.
'put in' is the first definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Perhaps there's an association between them I don't understand?
'charge' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for prime that I've seen before include "golden age?" , "Foremost" , "Two for one" , "Of superior grade" , "hour for prayer" .)