NOT A TEACHER
(1) By any chance, are you able to get a copy of Mr. Michael Swan's Practical
English Usage? He discusses this matter in detail.
(2) Mr. Swan says that sometimes there is no great difference:
We need (some) cheese. / I didn't buy (any) eggs.
(3) In other cases, there is a difference:
We've planted some roses. (The speaker doesn't say how many)
I like roses . (No idea of number)
Would you like some more milk? (Indefinite amount -- as much as the listener wants.)
We need milk, sugar, and eggs. (The speaker is thinking of the things that are needed, not of the amounts.)
Regarding your "scissors" and "good films" sentences, let's wait for a teacher to
answer, for I do not want to give you any wrong answers.
- For Teachers