Some special verbs (linking verbs) behave like the verb to be. Instead of an object the verb is followed by something called a complement. The complement may be a noun or an adjective, so there are two types of S-V-C sentences: S-V-C(noun) and S-V-C(adj). In either case, the complement describes the subject.
        It is important to remember that S is always an item in the category described by C(noun). If you find a sentence where that is not the case, you probably need EITHER to change the verb OR put a preposition in front of the noun.

Subject	Verb	Noun Complement	extra = plus a
My cousin Laura	is	a police officer.	.
Those two women, Tootsy and Mrs. Doubtfire	are	men	in disguise.
Subject	Verb	Adjective Complement	when, where, how, etc.
Those girls	look	very happy.	.
Nothing	is	impossible	when you are young.
We all	feel	sorry	for poor John.

There is a relationship between adjective pairs of feeling (usually ending in -ing and -ed) and the verbs that they come from. It can be clearly seen in a comparison of their basic sentence patterns.

.	Subject	Verb	O / C	extra = plus a
S-V-C	Action movies	are	exciting.	.
S-V-O	Action movies	excite	Bob.	.
passive	Bob	is excited	.	by action movies.
S-V-C	Bob	gets	excited	when he watches action movies.

So we have exciting movies and excited people (like Bob). Other adjective pairs that follow this pattern include shocking / shocked; interesting / interested; and frightening / frightened.