Female changes flags (7)
I believe the answer is:
falters
'female changes flags' is the definition.
The definition and answer can be both to do with communicating as well as being verbs in their -s form.
Perhaps you can see an association between them that I don't see?
'changes flags' is the wordplay.
I cannot quite see how this works, but
'changes' could be 'alters' ('alter' can be a synonym of 'change') and 'alters' is present in the answer.
A single letter 'f' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for falters that I've seen before include "Stumbles, hesitates" , "'Loses confidence, begins to fail (7)'" , "Moves unsteadily, stumbles" .)