Here we have our simple subject men modified by the adjectives, the, busy and industrious, and also by the adjective phrase, with families. So the complete subject of the sentence now is, the busy, industrious men with families.

Our predicate is still the single verb work. Let us now enlarge the predicate. We have found that adverbs are used to modify verbs, and so we may say:

Our simple predicate, work is now enlarged. It is modified by the adverb, hard and the adverb phrase, in the factory. So our complete predicate is now, work hard in the factory.

404. These sentences with the simple subject and the simple predicate and their modifying words and phrases form simple sentences.

A simple sentence is one which expresses a single statement, question or command.

405. A simple sentence, therefore, will contain but one subject and one predicate. The subject may be a compound subject and the predicate may be a compound predicate, but still the sentence expresses a single thought. For example: The boys sing. This is a simple statement with a simple subject and a simple predicate. Then we may say: The boys sing and play. We still have a single statement, but a compound predicate, sing and play.

Now we may make a compound subject, and say, The boys and girls sing and play, but we have still a single statement, for both predicates are asserted of both subjects. So, The boys and girls sing and play, is a simple sentence.

If we say, The boys sing and the girls play, we have a compound sentence, composed of two simple sentences, The boys sing, The girls play.