Overview
This section will serve as a basic overview of sentences. Each topic will be discussed in more detail in subsequent chapters.
Phrases
A phrase is a group of words which contains neither a subject nor a verb. (It may, however, contain a verbal form such as an infinitive, a participle, or a gerund.) http://writing-program.uchicago.edu/resources/complex-sentences.htm
Clauses
A clause is a group of words containing at least a subject and a verb (the baby ate), and frequently it lets its hair down by containing some kind of a complement as well (the baby ate the goldfish). There are two kinds of clauses: independent and dependent. http://writing-program.uchicago.edu/resources/complex-sentences.htm
Forms
There are three forms of a sentence: simple, compound, and complex, and one combined form: compound-complex.
Compound-complex
It is a sentence which is made to by joining two or more simple sentences.
Purposes
Sentences are created for four main reasons: to declare, to command, to question, and to exclaim.