Subject and predicate
A subject and a predicate are the two components that form every complete sentence.
The subject refers to what, or whom, the sentence is about, whilst the predicate provides information about the subject. In the examples below, the subject of the sentence will be highlighted and the predicate will be in italics.
- Mary sings.
- Mary and her mother went to the shops.
To easiest way to determine the subject of a sentence is to first isolate the verb and then form a question by placing "who?" or "what?" in front of it. The answer to the question is the subject.
So, in the example "The fans in the stadium screamed loudly," the verb is screamed. Asking the question, "Who screamed loudly?" gives the answer - and thus the subject: "The fans in the stadium". The predicate provides us with more information about the subject, in this case it tells us they "screamed loudly."
One exception to this, is an imperative sentence, which gives a command or order. In this case, the subject — which is always "You" — is not stated, but is rather understood to exist in front of the verb, within the context of the sentence.
Thus, while a command like "Come here!" might not appear to have a subject before the verb (come), it is understood that "you" is the subject of the imperative sentence.
Some languages allow omission of the subject pronoun if it is clear from the verb form. For example, in Spanish, Lo quiero, "I want it," is a complete sentence, even though the subject (yo, "I") is omitted, since the verb ending makes it clear that the subject is first person singular. Such languages are called pro-drop (or pronoun-dropping) languages. Some dialects of English showed some degree of pro-drop, at least in the second person singular, into the nineteenth century, as evidenced by Moby-Dick.
If the verb is a transitive verb in the active voice, the predicate contains one or more nouns or pronouns, which are the objects of the verb. If the verb is intransitive or is in a voice other than in the active voice, by definition there is no object. If the verb is doubly transitive, there are both a direct object (the thing on which the action is performed) and an indirect object (a person or thing that is the beneficiary of the action). Consider the following examples:
- Mary sang. (The verb is used in its intransitive sense, so there is no object).
- Mary sang a song. (The object is "a song.")
- Mary sang me a song. (The indirect object is "me," and the direct object is "a song.")