Turning points (6)
'turning points' is the definition.
The definition and answer can be both man-made objects as well as being plural nouns.
Maybe you can see a link between them that I can't see?
'points' is the wordplay.
I cannot quite see how this works, but
'points' could be 'es' (E is an example) and 'es' is present in the answer.
The remaining letters 'hing' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for hinges that I've seen before include "A door swings on them" , "Flexible joints" , "Movable joints between lid and box, say" , "Doors swing on them" , "Depends on - like door?" .)
'turning points?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Another definition for knobs that I've seen is " Rounded projections or protuberances".)