When writing a paragraph, the most basic unit of construction is the sentence, or a group of words placed together to form a singular idea. Sentences come in a variety of lengths and structures, and they can become quite complex and long. However, sentences can also be simply constructed and very brief. Such sentences are labeled simple. A simple sentence is exactly what its name implies: a sentence of simple construction: it contains only one subject and one predicate, and is devoid of any subordinate or dependent clauses. This type of sentence is the most basic type of sentence written, and is often brief and to the point.
For the sake of clarification, let's define the important terms mentioned above. The subject of a sentence is the actor or "doer" of the sentence. The subject causes the action, which is expressed in the verb. The verb is part of the predicate, which is the part of the sentence that shows what the subject has done. The predicate includes the verb and any other descriptors, like adverbs, which describe how a verb is performed; and direct objects, or something acted upon.
An example of a simple sentence follows:
--The dog runs.
In this example, the sentence contains only one subject--the dog--and one predicate, which in this case is the verb "runs." No other clauses--or groups of words with a subject and a predicate that do not form complete sentences--follow the original subject and predicate.
Here is another example:
This one-word sentence has an implied subject. The complete sentence would look like this, if the subject was present:
-- (You) wait!
So, in this case, the subject is the implied "you" and the predicate is the verb, "wait."
A simple sentence does not always necessarily have to be as brief as the previous examples. Below is an example of a longer one:
--John chased the ball quickly.
The subject in this sentence is John; the predicate is "chased the ball quickly." The predicate includes the verb "chased," a direct object "the ball," and an adverb that describes how the verb was performed, "quickly."
While simple sentences are generally brief and easy to construct, they can be very valuable when writing strong paragraphs. A good writer knows that several sentences in a row that mirror each other in style and structure can become boring to the reader; therefore, good writers will construct paragraphs using a combination of simple sentences, compound sentences, and compound-complex sentences. The simple sentence is a good place to start if you are just learning to write, but once you have mastered it, be sure to move on to longer, more complex sentence forms.