Left turn, then ask about a capital (6)
I believe the answer is:
lusaka
'capital' is the definition.
(capital of Zambia)
'left turn then ask about a' is the wordplay.
I cannot really see how this works, but
'left' could be 'l' (common abbreviation) and 'l' is located in the answer.
'turn' could be 'u' (a 'U-turn' is a kind of turn) and 'u' is located in the answer.
an anagram of 'ask' is 'sak' which is within the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for lusaka that I've seen before include "African capital - UK alas (anag)" , "Zambian city" , "Central African capital" , "Zambian capital" , "Capital of Zambia" .)