Classification of sentence

1.1. Simple sentence
Every complete sentence contains two parts: a subject and a predicate. The subject is what (or whom) the sentence is about, while the predicate tells something about the subject. In the following sentences, the predicate is enclosed in braces ({}), while the subject is highlighted.
Judy {runs}.
Judy and her dog {run on the beach every morning}.
To determine the subject of a sentence, first isolate the verb and then make a question by placing "who?" or "what?" before it -- the answer is the subject.
The audience littered the theatre floor with torn wrappings and spilled popcorn.
The verb in the above sentence is "littered." Who or what littered? The audience did. "The audience" is the subject of the sentence. The predicate (which always includes the verb) goes on to relate something about the subject: what about the audience? It "littered the theatre floor with torn wrappings and spilled popcorn."
Unusual Sentences
Imperative sentences (sentences that give a command or an order) differ from conventional sentences in that their subject, which is always "you," is understood rather than expressed.
Stand on your head. ("You" is understood before "stand.")
Be careful with sentences that begin with "there" plus a form of the verb "to be." In such sentences, "there" is not the subject; it merely signals that the true subject will soon follow.
There were three stray kittens cowering under our porch steps this morning.
If you ask who? or what? before the verb ("were cowering"), the answer is "three stray kittens," the correct subject.
Simple Subject and Simple Predicate
noun or pronoun (or more) that, when stripped of all the words that modify it, is known as the simple subject. Consider the following example:
A piece of pepperoni pizza would satisfy his hunger.
The subject is built around the noun "piece," with the other words of the subject -- "a" and "of pepperoni pizza" -- modifying the noun. "Piece" is the simple subject.
Likewise, a predicate has at its centre a simple predicate, which is always the verb or verbs that link up with the subject. In the example we just considered, the simple predicate is "would satisfy" -- in other words, the verb of the sentence.
A sentence may have a compound subject -- a simple subject consisting of more than one noun or pronoun -- as in these examples:
Team pennants, rock posters and family photographs covered the boy's bedroom walls.
Her uncle and she walked slowly through the Inuit art gallery and admired the powerful sculptures exhibited there.
The second sentence above features a compound predicate, a predicate that includes more than one verb pertaining to the same subject (in this case, "walked" and "admired").
The job of grammar is to organize words into sentences, and there are many ways to do that (or we could say, Words can be organized into sentences in many different ways). For this reason, describing how to put a sentence together isn't as easy as explaining how to bake a cake or assemble a model plane. There are no easy recipes, no step-by-step instructions. But that doesn't mean that crafting an effective sentence depends on magic or good luck.
Experienced writers know that the basic parts of a sentence can be combined and arranged in countless ways. So as we work to improve our writing, it's important to understand what these basic structures are and how to use them effectively.
We'll begin by introducing the traditional parts of speech and the most common sentence structures. For practice in shaping these words and structures into strong sentences, follow the links to the practice exercises, examples, and expanded discussions.