Am I not able to handle a type of spanner? (10)
I believe the answer is:
cantilever
'am i not' is the definition.
I can't judge whether this defines the answer.
'able to handle a type of spanner?' is the wordplay.
'able' becomes 'clever' (I've seen this before).
'to handle' indicates putting letters inside (handle can mean receive or take possession of).
'a type of spanner?' becomes 'anti' (I can't explain this - if you can you should believe this answer much more).
'clever' placed around 'anti' is 'CANTILEVER'.
(Other definitions for cantilever that I've seen before include "bridge design" , "support at one end" , "Projecting beam fixed at one end" , "Projecting mass" , "Beam supported at only one end" .)