A single clause standing alone is a ______ sentence?

Here's why:

* Clause: A clause is a group of words containing a subject and a verb.

* Simple Sentence: A simple sentence contains only one independent clause (a clause that can stand alone as a complete thought).

Example:

* The cat slept. (This is a single clause with a subject "cat" and verb "slept".)

Let me know if you'd like more examples!