Understanding Tag Questions in English Grammar

The question asks us to find the most appropriate option to replace the underlined segment "isn’t it ?" in the sentence: "During foggy weather, flights are often cancelled, isn’t it ?" This involves understanding how to form a correct tag question.

Forming Correct Tag Questions

A tag question is a short question added to the end of a sentence. It's used to ask for confirmation or to invite a response. The formation of a tag question depends on the main clause:

• If the main clause is positive, the tag question is usually negative.
• If the main clause is negative, the tag question is usually positive.
• The tag question uses the auxiliary verb from the main clause and the pronoun corresponding to the subject of the main clause.

Analyzing the Sentence and the Tag Question

Let's break down the given sentence:

"During foggy weather, flights are often cancelled, isn’t it ?"

The main clause is: "During foggy weather, flights are often cancelled".

Let's identify the key components of the main clause:

• Subject: "flights". This is a plural noun. The pronoun that replaces "flights" is "they".
• Verb Phrase: "are often cancelled". This is in the passive voice. The auxiliary verb here is "are".
• Main Clause Type: The main clause "flights are often cancelled" is positive (it does not contain words like 'not', 'never', etc.).

Based on the rules for tag questions:

• Since the main clause is positive, the tag question must be negative.
• The auxiliary verb from the main clause is "are". So, the negative form of the auxiliary verb needed for the tag is "aren't".
• The subject is "flights", which corresponds to the pronoun "they". So, the pronoun needed for the tag is "they".

Therefore, the correct tag question should be "aren’t they?".

Evaluating the Options for Tag Question Substitution

Let's look at the provided options:

1. do they: This tag uses the auxiliary "do" and is positive. The main clause uses "are" as the auxiliary, and the tag needs to be negative. So, this is incorrect.
2. aren’t they: This tag uses the auxiliary "aren't" (negative form of "are") and the pronoun "they". This correctly matches the auxiliary verb ("are") and the subject ("flights" → "they") of the positive main clause ("flights are often cancelled"). This option follows the rules for forming tag questions.
3. No substitution required: The original tag is "isn’t it ?". This tag uses the singular auxiliary "is" and the singular pronoun "it". This does not match the plural subject "flights" and the auxiliary "are" used in the main clause. Therefore, a substitution is required.
4. haven’t they: This tag uses the auxiliary "haven't". The main clause uses "are" as the auxiliary. So, this auxiliary does not match, making the tag incorrect.

Comparing the options, "aren’t they" is the only one that forms a grammatically correct tag question for the given sentence.

Conclusion on Correcting the Tag Question

The original sentence has an incorrect tag question because "isn't it?" does not agree in number or auxiliary verb with the subject "flights" and auxiliary "are" in the main clause. The correct tag should reflect the plural subject "flights" (pronoun "they") and the auxiliary "are" in a negative form because the main clause is positive. Thus, "aren't they" is the correct substitution.

Putting these requirements together, the correct tag question is "aren’t they?".

Revision Table: Key English Grammar Points

Additional Information on English Grammar

Understanding tag questions is crucial for natural-sounding English conversation and correct writing. While the basic rules are straightforward, some exceptions exist, particularly with specific subjects or tenses. However, for standard sentences like the one discussed, the rule of matching the auxiliary verb and using the correct pronoun for the subject holds true.

Always identify the core subject and the auxiliary verb (or main verb if 'be', 'have', or 'do' are main verbs in certain structures) in the main clause before forming the tag. Pay close attention to whether the subject is singular or plural to choose the correct pronoun for the tag.