What is the simple subject in an interrogative sentence?

The simple subject in an interrogative sentence (a question) is the same as in any other sentence: the noun or pronoun that performs the action of the verb.

Here's how to find it:

1. Identify the verb: The verb is the word that describes the action or state of being.

2. Ask "Who?" or "What?" before the verb: The answer to this question will be the simple subject.

Example:

* Question: Who ate the pizza?

* Verb: ate

* Simple Subject: Who (the pronoun)

Here's another example:

* Question: Did the cat catch the mouse?

* Verb: did catch (did is an auxiliary verb, the main verb is catch)

* Simple Subject: cat (the noun)

Important Note: Sometimes the subject might be implied, especially in short questions. For example:

* Question: "Are you coming?" (The implied subject is "You").

Let me know if you'd like more examples!