Sense you have an instinctive aptitude for (4)
I believe the answer is:
feel
This could be a double definition.
'sense you' is the first definition.
'feel' can be an answer for 'sense' (synonyms). I'm not sure about the 'you' bit.
'have an instinctive aptitude for' is the second definition.
'feel' can be an answer for 'have' (thesaurus). I am not certain of the 'an instinctive aptitude for' bit.
Can you help me to learn more?
(Other definitions for feel that I've seen before include "Experience (an emotion)" , "Fondle" , "Sense or touch" , "Instinct" , "impression" .)