To go about half a mile, he needs a taxi (5)

'he needs a taxi' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'to go about half a mile' is the wordplay.
'to go' becomes 'cab' (I am not sure about this - if you are sure you should believe this answer much more).
'about' is an insertion indicator.
'half a' suggests halving the letters.
'mile' cut in half is 'le'.
'cab' placed around 'le' is 'CALEB'.

Can you help me to learn more?