Think of baby sentences:

              Johnny hungry.            Cat run.

English sentences are composed of a topic and something said about that topic, commonly referred to as the subject and predicate.

         SENTENCE         =           SUBJECT         +           PREDICATE

The subject and predicate are often described as a topic and a comment, what is being talked about (the subject) and what is being said about it (the predicate).    Each of these elements is characterized by a combination of three elements or perspectives:

·          a position or slot within a sentence

·          a certain form or type of grammatical construction

·          a certain meaning

Thus the subject of a sentence typically

·          occurs at the beginning of the sentence (position),

·          consists of a noun phrase (form), and

·          indicates the topic of the discussion (meaning).   

The predicate

·          follows the subject,

·          starts with a verb indicating an action or state of being, and

·          conveys a thought about the subject.

The surest test of the complete subject in a sentence is to turn a statement into a yes/no question.

               All men are created equal.

Make a yes/no question

   Are all men          created equal.

The subject ( all men ) is the part around which the initial question word ( are ) moves.

              Are All men are created equal.

________

With some sentences you have to make the verb emphatic to form a question—for example, change ran into did run —to pick up the part of the verb that moves forward to make the    question.

              He                ran to the store.

              He     did       run to the store.

Did        he                run to the store?.

Here the verb did moves around the subject He.

A subject and predicate, together, form a simple sentence.    As used here, the term    "simple" refers to the basic structure of a sentence.    Simple sentences can be short or long, and can express simple or complex thoughts and may contain complex constructions, but the basic structure of the sentence is simple. Here are two simple sentences:

              John ate spaghetti.

The boy from Conosha with the funny earring in his left ear devoured a dish of delicious Italian pasta a la Milanese.

These two sentences have the same structure:

           John
           ate
           spaghetti.

           The boy from Conosha with the funny earring in his left ear
           devoured
           a dish of delicious Italian pasta a la Milanese.

Both are simple sentences from a structural point of view.    They both consist of    a subject and a predicate indicating what the subject did.    They are both composed of two noun phrases and a verb.    They both can be reduced with pronouns to

           He ate it.

Note that length alone does not determine structure, although it is often a factor.    We are concerned with the complexity of structure, not length.

Finally, besides the pronoun test, another test of a simple sentence is that we generally cannot leave any portion of the original sentence out without significantly changing the meaning.

Any discussion composed only of simple sentences would seem childish in expression. While simple sentences are useful for emphasis or clarity, as when summing up an argument, simple sentences alone do not allow for expressing complex thoughts. They are not conducive to asserting relationships or qualifying thoughts. To develop a sentence further we have to add stuff. This can be done in one of two ways:

·          we can simply multiply the elements that are there, or

·          we can add additional elements.

The first instance produces what is known as compound sentences, the second complex sentences. Complex is the more general term.    It suggests a degree of additional structure beyond a simple sentence.    Compound refers to a specific and limited type of complexity.

Series -- Compounding Elements

The term "compound" can be interpreted as "repeating" or "multiple." In a compound sentence one or more elements are simply repeated. The subject can be multiple

              The boy, his sister, and his dog went swimming.

              (1) The boy,

   (2) his sister, and

   (3) his dog                 

went swimming.

The verb may be compound

              They ran, swam, and laughed..

              They     (1) ran,

 (2) swam, and

  (3) laughed..

A full predicate may consist of a series of remarks:

              He    moved here, found a job, and sent my kids to school.

              He             (1) moved here,

 (2) found a job, and

  (3) sent my kids to school.

Two or more sentence can be compounded into one:

              This is where I call home; this is where I'll die.

              (1) This is where I call home;

  (2) this is where I'll die.

or

This is where I call home, so this is where I'll die.       

             (1) This is where I call home,

  so

(2) this is where I'll die.            

Here we have two simple sentences linked together.    The term "compound sentence" is generally used to describe such cases.   

When individual elements within a sentence are repeated, the series is divided by commas. The comma stands for, in effect, the word and .    The comma before the final item, before and , is often optional, but it is used here to make clear that the final two elements are not a pair, as in milk, bacon and eggs-- as opposed to the three items milk, bacon, and eggs. .

When sentences are compounded, they are divided by and, a semicolon, or by a compounding term and a comma.

Sentence one               and          sentence two

Sentence one               ;                           sentence two

              Sentence one             ;    however           sentence two.

Compound sentences are commonly joined with and , but , or , nor , so , yet and for .