Stranger called about single mark in Spanish (7)
I believe the answer is:
cedilla
'mark in spanish' is the definition.
'cedilla' can be an answer for 'mark' (cedilla is a kind of mark). I am unsure of the 'in spanish' bit.
'stranger called about single' is the wordplay.
'stranger' indicates anagramming the letters.
'about' indicates putting letters inside.
'single' becomes 'I' (I as in one).
'called' with letters rearranged gives 'cedlla'.
'cedlla' going around 'i' is 'CEDILLA'.
Can you help me to learn more?
(Other definitions for cedilla that I've seen before include "The mark under the letter C in Spanish" , "Mark suggesting a 'c' should be pronounced an 's'" , "Mark under the letter C in French" , "I called (anag.)" , "Small mark placed below C in Portuguese and Catalan, for example" .)