What part of speech is is?

"Is" can be a few different parts of speech depending on its context. Here's a breakdown:

1. Verb (most common): This is the most common usage. It acts as a linking verb, connecting the subject to a predicate.

* Example: The sky is blue. (Connects "sky" to "blue")

2. Auxiliary Verb: "Is" can be part of a verb phrase when used with other verbs.

* Example: The cat is sleeping. (part of the verb phrase "is sleeping")

3. Pronoun (rare): In very specific contexts, "is" can stand in for a noun, usually in a question.

* Example: "Who is going to the party?" ("Is" represents the person going)

To determine the part of speech of "is", you need to look at the sentence and its role within the sentence.