What may start a sentence in English at school, say (7)
I believe the answer is:
subject
'school say' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for subject that I've seen before include "Theme, topic" , "A national - topic of discussion" , "Person under 26?" , "One is under the authority of royalty" , "issue" .)