14. Which of these combinations of words are sentences and which are not?

Busy men does not express a complete thought. We are wondering busy men do what? But, men travel is a complete thought. It makes sense and forms a sentence, and tells us what men do. In the words, busy men, we have spoken the name of something but have made no assertion concerning it. In the two words, men travel, we have spoken the name men and we have told what they do.

If we were walking down the street together we might say:

Or if we were discussing the class struggle, we might say:

In every one of these six groups of words we have a complete thought expressed. Each of these groups of words we call a sentence.

15. A sentence is a group of words expressing a complete thought.

Exercise 2