Make fishy complaints? (4)
I believe the answer is:
carp
'make' is the definition.
The definition and answer can be both to do with communicating as well as being verbs in their base form.
Perhaps they are linked in a way I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for carp that I've seen before include "Fish - complain" , "Nagging fish?" , "Cavil - fish" , "ish" , "Continuously find fault" .)