if that's ok

classroom is all one word, so doesn't need a hyphen.

ooh please - that would help immensely!

You're a Metallica fan I take it? This phrase basically means 'for whom the bell rings' but generally in a church because the word 'toll' implies that the bell is large and making a louder sound than a smaller bell ringing. For me, I get the

"so they know what they have done" or even better... "so they realise what they have done"

"David showed some interest and smiled at me" I think that's correct...

You can say "you should feel ashamed of your behaviour" but in my opinion it is better to say "you should feel ashamed of yourself" You can't say "you should feel ashamed of you" because you shouldn't use the same pronoun in 1 sentence. instead,

oh yeah, I didn't think of that. I guess it is context dependant because it could mean either, depending on if it is a question or if it is an exclamation.

I think it would be better to say 'we went clubbing over the new year' or 'we went clubbing on new years eve'

'Or what' is generally a rhetorical question (a question that needs no answer because the answer is implied by the question). Therefore, in this case, 'is this scary or what?' is implying that the speaker thinks that it is scary, not really asking