Can end of tack give sharp pain? Step on it (4,5)
I believe the answer is:
look smart
'sharp pain? step on it' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'can end of tack give' is the wordplay.
'can' becomes 'loo' (both can informally mean toilet).
'end of' suggests the final letters.
'give' becomes 'smart' (I can't explain this - if you can you should believe this answer much more).
The last letter of 'tack' is 'k'.
'loo'+'k'+'smart'='LOOK SMART'
Can you help me to learn more?
(Other definitions for look smart that I've seen before include "Act quickly" , "Be quick!" , "appear fashionable and upmarket" .)