"It's the basis of ordinary etiquette / to be sure of your subject and your predicate." This lyric from a children's play about acceptable grammar is certainly true; however, not many people can point out the predicate in a sentence (even if they are sure of the subject).
The predicate of a sentence is the part that modifies the subject in some way. Because the subject is the person, place, or thing that a sentence is about, the predicate must contain a verb explaining what the subject does and can also include a modifier.
A simple predicate is the word that shows the action in a sentence. It is used to tell you what the subject of the sentence does. Look at some of the shorter sentences in the English language:
These sentences are very simple examples of what predicates are, since the predicate is expressed entirely by one verb. A simple predicate may also be a short verb phrase.
Some more examples of simple predicates are as follows. The simple predicate is in bold in each example.
In addition to simple predicates, there are also compound predicates. A compound predicate gives two or more details about the same subject and has two or more verbs joined by a conjunction. For example: "She visited her cousins and met all their friends." In this example, "she" is the subject and "visited" and "met" are the predicates joined by the conjunction "and".
Some more examples of compound predicates are as follows. The compound predicate is in italics in each example.
A complete predicate is the verb that shows the action and also the modifying phrase that completes the thought, basically everything in the sentence that isn't the subject.
Some examples of complete predicates are as follows. The complete predicate is underlined.
"I am" is often described as the shortest sentence in the English language, but this is not exactly true. While it can be a complete thought and does contain a subject and a verb, it doesn't explain what "I am." An additional piece of the phrase is usually necessary to complement the verb. When you answer "I am," you are usually leaving out an implied word which completes the sentence.
Whatever you add to "I am" technically forms the predicate of the sentence. For example: "I am playing guitar." You must add "playing guitar" to complete what you are doing in the sentence. Another example: "I am tired." The word "tired" is used to describe what you are.
Now that you know "I am" is not technically a complete sentence, you'll probably be quick to notice other examples that seem like complete sentences but lack a predicate, such as "I can" and "I will." What might confuse you is the sentence that seems to lack a subject.
There are two things you'll need to understand before this example will make sense.
As surprising as it may sound, the shortest complete sentence in the English language is the imperative, "Go!" How can this be? After all, "go" is a verb seemingly without a subject or a predicate.
Every sentence has two parts: subject and predicate. The predicate is used to tell the reader what the subject does. It contains a verb and shows action. Predicates can be one verb or verb phrase (simple predicate), two or more verbs joined with a conjunction (compound predicate) or even all the words in the sentence that give more information about the subject (complete predicate). To find the predicate, simply look for what the subject is doing.