Adjectives clauses

I bought a new (adjective) book (noun).

An adjective modifies (changes a little) a noun. 
An adjective gives a little different meaning to a noun. It 
describes or gives information about a noun.
An adjective usually comes in front of a noun.

1- An adjective:
Adjectives describe nouns. They are usually before the noun. 
Sometimes, they are alone after the verb.

They are serious questions.
These equations are serious.

There are 2 basic positions for adjectives:
 Before the noun 
 After certain verbs 


1-1 - Adjective before noun:
We sometimes use more than one adjective before the noun:
The correct order for two or more adjectives is:
1.1.1 The general order is: opinion, fact:
Opinion: is what you think about something. 
Fact: is what is definitely true about something.

1.1.2 The normal order for fact adjectives is: 
Size, age, shape, color, material, origin:
Opinion, fact, size, age, shape, color, material, origin noun
A strange, true, big, old, square, black, wooden     Chinese table 

1.1.3 Determiners usually come first, even though they 
are fact adjectives:
Articles (a, the) 
Possessives (my, your...) 
Demonstratives (this, that...) 
Quantifiers (some, any, few, many...) 
Numbers (one, two, three) 
When we want to use two color adjectives, we join them with 'and':

She was wearing a long, blue and yellow dress. 

1-2- Adjective after Verb:
1-2-1 after Verb:
We can use an adjective after certain verbs: 
(Be, become, get, seem, look, feel, sound, smell, taste).

Even though the adjective is after the verb, it does not 
describe the verb. It describes the subject of the verb 
(Usually a noun or pronoun).
Examples:
 
Because she had to wait, she became impatient. 
The examination did not seem difficult. 
Your friend looks nice. 
Dinner smells good tonight. 
This milk tastes sour. 
Some times you smell good.
1-2-2 After BE:
The word was populated.      
The word is overpopulated.
The past participle form of the verb is often used as 
an adjective as follow:
Subject + BE + past participle 

 
2- Adjective clause:
I bought a book (noun), which has blue pages (adjective clause)
An adjective clause modifies a noun. It describes or gives 
information about a noun.

An adjective clause follows a noun.

Using who & whom in adjective clauses:

The woman was strange. She had a blue hat.

She is subject pronoun (She: refers to the woman)

To make an adjective clause, we can change She to Who:
The woman who has a blue hat was strange. 

Who is a subject pronoun (Who: refers to the woman)

An adjective clause immediately follows a noun it modifies.

The woman was strange. I saw her.

Her is an object pronoun (Her: refers to the woman)

To make an adjective clause, we can change her to whom

The woman whom I saw was strange.

Whom is an object pronoun (Whom: refers to the woman)

An adjective clause immediately follows a noun it modifies 
and begins in the object pronoun (whom).

NOTE:

The subject pronoun cannot be omitted.
The object pronoun can be omitted.
The woman whom I saw was strange.
= The woman I saw was strange.
THAT is used either for Who or Whom.
The woman who has a blue hat was strange.
= The woman that has a blue hat was strange.  

The woman whom I saw was strange.
= The woman that I saw was strange.
 Formal & informal:
The woman whom I saw was strange. (Formal)
The woman who I saw was strange. (Informal)
 Which:
Who and whom are used for people. 
For things we use WHICH for either subject or object pronoun.
The book was new. It has blue pages
The book, which has blue pages, was interesting.
The book was interesting. I bought it
The book, which I bought, was interesting.
 THAT is used also for which (subject or object):
The book that has blue pages was interesting.
The book that I bought was interesting.
= The book I bought was interesting. (Can be 
omitted for an object)
 Who, whom, which, that can refer to both 
	singular and plural.
The woman who has a blue hat was strange.
The women whom I saw were strange.
The book that has blue pages was interesting.
The books I bought were interesting.
 Using prepositions in adjective clauses:

 
With subject pronoun:
The woman was strange. She looked at me.
The woman who (that) looked at me was strange.
No change.
With object pronoun:
The woman was strange. I looked at her.
The woman whom I looked at was strange
The woman that I looked at was strange
The woman I looked at was strange
The woman at whom I looked was strange (very formal)
The cat has blue eyes. She lives with it.
The cat to which she lives has blue eyes.

(The preposition: comes before either whom or which ONLY, 
not that, and the pronoun cannot be omitted)

Whom, that, which can be used as the object of the 
preposition in an adjective clause)

Using whose in adjective clauses:
The woman was angry. Her cat was stolen. Her sister was lost 
and her earrings were broken.

Adjective clauses:
The woman             whose cat was stolen was angry.
The woman             whose sister was lost was angry.
The woman             whose earrings were broken was angry.
Whose shows possession. It can be used with either people 
or things, either singular or plural.