One after another articulate apprentice (2,4)
I believe the answer is:
in turn
'one after another' is the definition.
(in turn means one by one)
'articulate apprentice' is the wordplay.
'articulate' shows a homophone (sound like) (articulated or said out loud).
'apprentice' becomes 'intern' (I've seen this in another clue).
'intern' sounds like 'IN TURN'.
(Other definitions for in turn that I've seen before include "One after another" , "in an orderly fashion" , "orderly treatment" , "not out of place" , "a succession of things happen" .)