I searched, didn't find anything, and I just hope I'm not stupid for not finding a topic on this...
So, how does the thing about the N.E.W.T.s work?
You get your O.W.L. marks after fifth year. I imagine the letter including a list of available NEWT subjects and which mark the teacher wants to see from their students. (For example, it reads: Charms, Professor Flitwick: E). But then again I thought: If it worked like this, Harry would have known about Slughorn teaching potions, wouldn't he? So maybe a list is distributed at the end of fifth year.
But they do have to know about what marks they need to continue a subject, else they can't buy books in time, and apparently people did so, because Harry and Ron are the only ones who have to send an owl for a book in sixth year, and I doubt that students only continue subjects in which they achieve O's.
Now, as for subjects they continue. Are there any restrictions, like there are earlier [I guess you have to take 2 of the electory (?? I mean, the subjects they choose in third year, Divination, CoMC, Arithmancy, Runes, Muggle Studies) and can't drop any core subjects] - you have to continue at least.. whatever, 3 subjects to NEWT level? Or do you think that if someone wanted to stay just for Herbology, they'd be allowed to?
Is there any evidence in the books?
And if you realize an NEWT subject is too hard, can you just drop out?
Is every subject continued to NEWT level?
Are the NEWT exams like the OWL exams, or do you think there are differences?
It would be great if anyone had answers or opinions or whatever...