Since we already have the concept of compounding, we need not spend any time on compound subjects, compound verbs, or compound complements. They are all possible. There are, however, four different possible types of complements, and thus there are four possible variations of the S/V/C pattern.
 

The four variations can be distinguished simply by making a question with the verb in the pattern (<Verb> +"whom" or "what"?). The answer to the question will determine both the pattern and, for those who are interested, whether the verb is transitive, etc. Some students have problems identifying types of complements, but the process is easy IF it is done in the following sequence.

      Having found the verb, and having found its subject (basically by using the question "Who or what + <verb>?"), move the "whom or what" after the verb to make the question "<Verb> whom or what? Then follow these steps:

      If nothing answers the question "Verb + whom or what?", the pattern is S/V. (The verb is intransitive.) Since nothing (zero) answers the question, we have something similar to what linguists call a "zero complement." [STOP: You have your answer.]

      If the word that answers the question "what?" after the verb is an adjective, the pattern is S/V/PA. (The verb is a linking verb.) [STOP: You have your answer.]

      If the word that answers the question is a noun (or pronoun) that renames the subject and the verb implies an equality or identity between subject and complement, the pattern is S/V/PN. (The verb is a linking verb.) For example:

     Ed remained a child. ("Remained" here means "was" and "continues to be.") 
     Bill became a teacher. (He "was" not, but now he "is.")

A sentence such as "Sleeping children resemble angels." implies that when they are sleeping, children equal angels, at least in appearance. "Angels" is therefore a predicate noun. 
 

[STOP: You have your answer.]

        If a word or construction answers the question "whom or what?" after a verb and is not a predicate noun or predicate adjective, it has to be an indirect or direct object. (The principle of exclusion is here combined with the principle of comprehensiveness: all verbs fall into one of four patterns, if a verb is not in pattern a, b, or c, then it must, by exclusion, be in d.) An indirect object indicates the person "for" or "to" whom something is done. (The verb is transitive.)

Please Note: In Level Two, you are expected to be able to identify single words that function as complements, but some complements consist of several words and may confuse you. You will not be expected to identify these complements. Simply concentrate on the complements that you can identify.