Here's why:
* Imperative sentences: These are commands or requests. They often omit the subject ("you") and the verb is implied.
* Example: "Close the door." (The implied verb is "close.")
* Interjections: These are short expressions of strong emotion. They typically don't have verbs.
* Example: "Ouch!"
* Phrases: These are groups of words that function as a unit, but don't express a complete thought. They often don't have verbs.
* Example: "After the rain."
However, most English sentences do have a verb, and they are essential for conveying a complete thought. The verb expresses the action or state of being in a sentence.