Appears to understand what has been written (5)
I believe the answer is:
seems
'appears' is the definition.
('seem' can be a synonym of 'appear')
'understand what has been written' is the wordplay.
I cannot quite understand how this works, but
'understand' could be 'see' (synonyms) and 'see' is found within the answer.
The remaining letters 'ms' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'to' is the link.
Can you help me to learn more?
(Other definitions for seems that I've seen before include "Appears, looks" , "Gives a certain impression" .)