I need help understanding simple subjects and simple predicates. The sentence is: What is keeping them?

I'm confused about which is the simple subject and simple predicate.
Thank you

http://www.chompchomp.com/terms/subject.htm

The simple subject is the noun or pronoun that is the subject without including any adjectives or phrases that modify it.

http://www.chompchomp.com/terms/verb.htm
The simple predicate (verb) is the main verb of the sentence, including any auxiliary verbs, but excluding any objects, complements, or modifiers.

In your sentence "What" is the simple subject.

In your sentence "is keeping" is the simple predicate.

The first thing to do is find the verb. In this sentence the verb (simple predicate) is is keeping.

Then ask who or what is doing this action? Which is the only word that answers that question? That is the subject.

I'll be glad to check your answer.

To understand the simple subject and simple predicate in the given sentence, "What is keeping them?", let's break it down:

The simple subject refers to the main noun or pronoun in the sentence, while the simple predicate refers to the main verb or verb phrase.

In this sentence, the simple subject is "What." It is a pronoun that acts as the subject of the sentence and refers to an unknown thing or reason.

The simple predicate is "is keeping," which is the main verb phrase. "Is" is the helping verb, while "keeping" is the main verb. Together, they form the present continuous tense, indicating an ongoing action.

To identify the simple subject and simple predicate in a sentence, you can follow these steps:

1. Identify the main noun or pronoun that the sentence is about. This is usually the subject and therefore the simple subject.
2. Look for the main verb or verb phrase that expresses the action or state of being. This is usually the predicate and therefore the simple predicate.

By breaking down the sentence and identifying the main elements, you can determine the simple subject and simple predicate.