English grammar error-spotting (question tags with ‘‘none’’—formal singular agreement expected): Read the sentence in four parts and choose the erroneous segment; select ‘‘No error’’ only if the whole sentence is correct. ‘‘None of the students attending your class / answered your questions / did they? / No error.’’

Given data

• Head word: ‘‘None’’
• Tag used: ‘‘did they?’’

Concept / Approach
In formal test English, ‘‘none’’ is often treated as singular (‘‘none has …’’), and the tag question agrees with the head word: ‘‘… answered your questions, did he?’’ While contemporary usage frequently allows plural agreement (‘‘did they?’’), the exam key expects singular.

Correction
‘‘None of the students … answered your questions, did he?’’ (Alternative formal: ‘‘… did any of them?’’)

Common pitfalls

• Automatically using plural ‘‘they’’ after ‘‘none’’ in contexts where the exam tests traditional singular agreement.

Final Answer
did they?