Didn’t you buy _________ when you went shopping?

Answer: any paper

Explanation: 'Paper' is usually an uncountable noun. In negative questions we use 'any' to ask whether some (unspecified) amount was bought, so 'Didn't you buy any paper when you went shopping?' is the natural phrasing.

• Why 'much paper' is not ideal: 'much' can be used in questions or negatives to focus on large quantity, but here the neutral way to ask whether any was bought is 'any paper'.

• Why 'no paper' is wrong: Using 'no' after 'didn't' creates a double negative and sounds ungrammatical. Use 'Didn't you buy any paper?' instead.

• Why 'a few paper' is wrong: 'A few' requires a countable plural noun (for example, 'a few sheets of paper' or 'a few papers'), so 'a few paper' is ungrammatical.

Examples: Didn't you buy any paper when you went shopping?