Where, in the country, Sarah went to work? (5)
I believe the answer is:
salop
'where in the country' is the definition.
The definition suggests a singular noun which matches the answer.
'sarah went to work?' is the wordplay.
'sarah' becomes 'sal' (Sally is a common pet form of Sarah).
'went to work?' becomes 'op' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'sal'+'op'='SALOP'
Can you help me to learn more?
(Other definitions for salop that I've seen before include "Shropshire (abbr.)" , "Telford here" , "Old county" , "Shropshire in short" , "Old name for Shropshire" .)