For a semidetached, it shows potential (7)
I believe the answer is:
promise
'potential' is the definition.
(I've seen this in another clue)
'for a semidetached it' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'a semidetached' becomes 'mis' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'it' becomes 'e' ('e' can mean 'electronic' which is similar to 'IT').
'pro'+'mis'+'e'='PROMISE'
'shows' is the link.
Can you help me to learn more?
(Other definitions for promise that I've seen before include "Pledge - my word!" , "Verbal or other commitment of one person to another" , "Betroth" , "Guarantee" , "Give one's word" .)