ADJECTIVE CLAUSE

An adjective clause—also called an adjectival or relative clause—will meet three requirements:

• First, it will contain a subject and verb.
• Next, it will begin with a relative pronoun [who, whom, whose, that, or which] or a relative adverb [when, where, or why].
• Finally, it will function as an adjective, answering the questions What kind? How many? or Which one?

The adjective clause will follow one of these two patterns:

relative pronoun or adverb + subject + verb

relative pronoun as subject + verb

Here are some examples:

Whose big, brown eyes pleaded for another cookie

Whose = relative pronoun; eyes = subject; pleaded = verb.

Why Fred cannot stand sitting across from his sister Melanie

Why = relative adverb; Fred = subject; can stand = verb [not, an adverb, is not officially part of the verb].

That bounced across the kitchen floor

That = relative pronoun functioning as subject; bounced = verb.

Who hiccupped for seven hours afterward

Who = relative pronoun functioning as subject; hiccupped = verb.

 Here are several examples of sentences with the adjective clauses underlined:

• Pizza, which most people love, is not very healthy.
• The people whose names are on the list will go to camp.
• Grandpa remembers the old days when there was no television. 
• Fruit that is grown organically is expensive.
• Students who are intelligent get good grades.
• Eco-friendly cars that run on electricity save gas.
• I know someone whose father served in World War II.
• Making noise when he eats is the main reason why Sue does not like to eat with her brother.
• The kids who were called first will have the best chance of getting a seat.
• Running a marathon, a race of twenty-six miles, takes a lot of training.
• I enjoy telling people about Janet Evanovich whose latest book was fantastic.
• The people waiting all night outside the Apple store are trying to purchase a new iPhone.
• "He who can no longer pause to wonder and stand rapt in awe is as good as dead." - Albert Einstein
• “Those who do not complain are never pitied.” - Jane Austen
• “People demand freedom of speech to make up for the freedom of thought which they avoid.” - Søren Kierkegaard
• “Never go to a doctor whose office plants have died.” - Erma Bombeck

Comic Example :

http://examples.yourdictionary.com/example-adjective-clauses.html
http://www.chompchomp.com/terms/adjectiveclause.htm
http://jesselonergan.blogspot.com/2011/03/adjective-clauses-boyfriends-and.html