Answer:

Explanation:

The correct auxiliary verb to fill in the blank in the given question is "do."

Usage of the Auxiliary Verb "do":

The auxiliary verb "do" is used to form questions and negative sentences in the present simple and past simple tenses. It is also used to add emphasis to a statement.

Examples of the usage of "do":

1. Questions: When we form questions in the present simple tense, we use the auxiliary verb "do" before the subject. For example:
- What do you do every Sunday?
- Note: In the given question, "do" is used before the subject "you" to form the question.

2. Negative Sentences: In negative sentences, we use the auxiliary verb "do" with "not" (don't/doesn't) before the main verb. For example:
- I don't like to go to the movies.
- She doesn't enjoy playing tennis.
- Note: The negative form of "do" (don't/doesn't) is used before the main verb to form negative sentences.

3. Emphasis: The auxiliary verb "do" can be used for emphasis in affirmative sentences. For example:
- I do love chocolate!
- She does play the guitar very well.
- Note: The auxiliary verb "do" is used to add emphasis to the statement.

Conclusion:

In the given question, "What do you do every Sunday?", the auxiliary verb "do" is used before the subject "you" to form the question. Therefore, option 'A' (do) is the correct answer.

The correct auxiliary verb to fill in the blank is "do." Here's why:
1. Identifying the question:
The question is asking about a habitual action or routine that the person does every Sunday.
2. Use of auxiliary verbs:
Auxiliary verbs are used to form questions and negative statements in English. They help to convey different meanings and tenses of the main verb. In this case, we need an auxiliary verb to form the question.
3. Eliminating options:
Let's analyze the given options one by one:
- Option B: "are"
- "Are" is the present tense form of the auxiliary verb "be." However, it is not suitable in this context because we are not asking about a state or condition.
- Example: "What are you doing every Sunday?" (asking about the person's current activity)
- Option C: "have"
- "Have" is the present tense form of the auxiliary verb "have." However, it is not suitable in this context because we are not asking about possession or ownership.
- Example: "What have you done every Sunday?" (asking about past actions)
- Option D: "shall"
- "Shall" is a modal auxiliary verb used to express future actions or suggestions. However, it is not suitable in this context because we are not asking about future plans or intentions.
- Example: "What shall you do every Sunday?" (asking about future plans)
- Option A: "do"
- "Do" is the present tense form of the auxiliary verb "do." It is suitable in this context as it is used to ask about habitual actions or routines.
- Example: "What do you do every Sunday?" (asking about the person's regular activities)
Conclusion:
Therefore, the correct auxiliary verb to fill in the blank is "do" (Option A).