Identifying Sentence Errors: Correcting Tag Questions

This question requires us to identify an error in the use of a tag question within the sentence "She has finished her homework, didn't she?" and select the correct alternative.

Understanding Tag Questions

Tag questions are short questions added to the end of a statement, typically used to seek confirmation or agreement. Forming a correct tag question involves following specific grammatical rules:

• The tag question uses the same auxiliary verb (or modal verb) as the main statement.
• The polarity of the tag is opposite to that of the main statement (positive statement requires a negative tag, and a negative statement requires a positive tag).
• The pronoun in the tag must correspond to the subject of the main statement.

Analyzing the Sentence: "She has finished her homework, didn't she?"

Let's break down the main statement:

• Subject: $She$
• Auxiliary Verb: $has$
• Main Verb: $finished$ (Past Participle)
• Tense: Present Perfect (formed with 'has' + past participle)
• Polarity: Positive

Forming the Correct Tag Question

Based on the rules:

• The auxiliary verb should be the same: $has$.
• Since the statement is positive, the tag must be negative: $hasn't$.
• The pronoun must match the subject: $she$.

Therefore, the grammatically correct tag question for the statement "She has finished her homework" is "hasn't she?".

The original sentence uses "didn't she?", which is incorrect because:

• It uses the auxiliary verb $did$ (from the Past Simple tense) instead of the correct auxiliary verb $has$ (from the Present Perfect tense).
• The main statement is in the Present Perfect tense, not the Past Simple tense.

Evaluating the Options

Let's examine each option based on the established rules:

• Option 1: $She has finished her homework, haven't she?$
  This is incorrect. While the tag is negative, $haven't$ does not agree with the auxiliary verb $has$ or the subject $she$.
• Option 2: $She has finished her homework, hasn't she?$
  This is correct. It uses the auxiliary verb $has$ (negated as $hasn't$) and the pronoun $she$, perfectly matching the main statement.
• Option 3: $She has finished her homework, doesn't she?$
  This is incorrect. The tag uses the auxiliary verb $doesn't$, which is related to the Simple Present tense and does not match the Present Perfect tense of the main statement ('has finished').
• Option 4: $She has finished her homework, don't she?$
  This is incorrect. The tag uses the auxiliary verb $don't$, which is inappropriate for the subject $She$ and the tense used in the main statement.

Conclusion

The error in the original sentence lies in the incorrect formation of the tag question. The correct tag question must use the auxiliary verb 'has' in its negative form 'hasn't' with the pronoun 'she'. Option 2 provides the correct tag question.