They manage to give warning, chaps (7)
I believe the answer is:
foremen
'they manage' is the definition.
The definition suggests an adverb but the answer is not.
'give warning chaps' is the wordplay.
'give' means one lot of letters go next to another.
'warning' becomes 'fore' (I've seen this in other clues).
'chaps' becomes 'men' (I've seen this before).
'fore'+'men' is 'FOREMEN'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for foremen that I've seen before include "Persons in charge" , "Overseers" , "Resembling a bird" , "They are in charge of workmen" , "Workers' leaders" .)