Does it store all the letters one writes? (8)
I believe the answer is:
alphabet
'letters one writes?' is the definition.
I know that 'letters' relates to this answer.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for alphabet that I've seen before include "Complete set of letters" , "Pale bath (anag.)" , "Confusing assortment of initials" , "Fundamental language components" , "Letters, symbols used in a writing system" .)