An adjective is a word which modifies a noun or pronoun by describing, identifying or qualifying words.

Kinds of Adjectives
(A) Proper Adjectives : Adjective formed from proper nouns.
e.g., Indian from India (proper noun)
First letter of proper adjective is always capital.
e.g., I love Indian culture very much.

(B) Possessive Adjectives : My, our, your, his, her, their, its, etc. These adjectives are always used before noun.

(C) Distributive Adjectives : Each, every, either, neither.
1. Each may be used for two and more than two while every is always used for more than two.
e.g., He gave this pen to every friend.

2..Either and neither are always used for two.
e.g., There are two boys in the room. Neither boy is tall.

3. No article is used before the noun used after the each, either, every and neither.

(D) Demonstrative Adjectives :
Definite :
this, that, these, these, such, same
Indefinite : a, an, certain, some, any, other, another etc.
1. A, an, another, this, that are always used with singular countable noun.
2. These, those, certain are always used with plural countable noun.
3. Such, the same, the other, any are used with both singular and plural countable noun.

(E) Numeral Adjective :
: definite numbers such as one, four etc.
Indefinite : Many, some, enough, few, various, all, most, numerous, several etc.
(i) The adjectives which tell about definite numbers are called cardinals while which tell about definite order are called ordinals. Cardinals are one, two, three etc.
Ordinals are first, second, third etc.
(ii) If in a sentence both cardinals and ordinals are used, then cardinals always followed the ordinals.
e.g., the first three chapters of the book are very important.

(F) Quantitative Adjectives : Much, little, whole, some, enough, all, most etc.
1. Much, little, whole are used for quantity only.
2. All, some, enough, most, sufficient etc. are used for both quantity and numbers.
3. Generally some is used in affirmative sentences and any is used in negative and interrogative sentences.
E.g., I shall buy some thing from this shop. I Will not buy anything from this shop.
But if interrogative is in request or command form than some replaces any.
e.g., Can I buy something from your shop.

(G) Qualitative Adjectives : Big, small, good, bad. ugly, beautiful.
e.g., This flower is very beautiful.
Adjective of quality can be used either before their nouns or after a verb.
e.g., She looked calm and quiet.

(H) Interrogative Adjectives : which and what
e.g., Which dish you like the most?
(i) Exclamatory adjective : what .
e.g., What a beautiful flower ?

Comparison of adjectives

1. Positive degree : It is used in one case only. e.g., Radha is good singer.
2. Comparative degree : It is used when there are two cases.
e.g., Radha is better than her sister.
3. Superlative degree : When more than two cases, this degree is used.
e.g., Radha is the best singer in the contest.

Important Rules to use of Adjectives

1, In place of than ‘to’ is used after senior, junior, inferior, superior, posterior, prior etc. More and most are also not used with above words.
(i) Ram is senior to Shyam.
(ii) She came prior to me.
Interior, exterior, minor, major, former, lower etc. are positive degree interiors. So neither more or most are used before them nor than or to after them.
e.g., The interior decoration of this house is excellent.

2. Positive degree is always used after comparatively or relatively.
e.g., This building is relatively close to my house.

3. (a) To is used after ‘prefer’ if comparison is between two nouns.
e.g., She prefers tea to coffee. (b) If comparison is between two infinitives then rather than is used after prefer. e.g., I prefer to sing rather than dance.

4. Positive degree with as is always used with so and as.
e.g., They are as intelligent as I am.

5. In comparisons using than, personal pronouns following than should be in the subjective case. e.g., I am taller than he. [In informal English, the objective case of a personal pronoun is often used after than. However this use is considered to be grammatically incorrect. e.g., I am taller than he.

6. Two comparative adjectives are not normally used in a sentence. But we can use rather with the adjective of comparative degree.
e.g., She is rather better today.

7. When we compare two qualities in the same person or thing we should not use comparative ‘er’ instead we should use ‘more’.
e.g., She is more clever than intelligent.

8. When one or more things are compared with a group to which they do not belong, the comparative form of an adjective is used while when one or more things are compared with members of a group to which they belong the superlative from of an adjective is used.
(i) The girls are cleverer than the boys.
(ii) Seema is the cleverest of all the girls in the class.

9. Two superlatives are not used in a sentence. 
(i)Ram is most strongest of all (incorrect).
(ii) Ram is strongest of all (correct).

10. ‘Other’ or ‘else’ should not be used with superlatives. e.g., She is most beautiful ofall girls (not all other girls).

11. With ‘like’ superlative ‘best’ and most are used but in such cases ‘the’ is not used before the superlative. e.g., Which of the toy do you like most ?

12. Usually ‘of‘ is used with the superlative but while talking about ‘place’ we should use ‘in’.
e.g., Kolkata is the dirtiest city in India.

13. ‘Kind’ and ‘sort’ refer to singular number. So ‘this’ and ‘that‘ should be used with them in place of ‘these’ and ‘those’.
e.g., I do not like this kind of shirt (in place of these kind).

14. There are some words like perfect, universal, complete, unique, extreme, full, excellent, golden, circular, full etc, we don’t make their comparative or superlative degree.

15. (a) Elder and Eldest are used for the persons having blood relations while older and oldest used for persons as well as for things.
(b) Elder is used with ‘to’ while older is used with ‘than’.
(i) My grandmother is the eldest member of our family.
(ii) Ram is older than Shyam.

16. Later, Latest, Latter, Last
Later and latest are used with reference to time while latter and last are used with reference to order or position.
Latest means new or very recent things while last means final.
(i) Between Riya and Reema, the latter is prettier.
(ii) This is the latest technology.
(iii)Lord Mountbaten was the last Governor General of India.

l7. Farther, Farthest, Further, Furthest
(a) All above words are used for geographical distances.
(b) Further means besides. It is usually used with abstract nouns to mean additional or extra.
e.g., No further discussion is needed in this matter. 

18. Nearest, Next 
Nearest is used to show distance while next is used for position. 

19. First and Foremost
First means that happens before all the other l while foremost means most important. 
(i) Neil Armstrong was the first to reach at the moon.
(ii) Indira Gandhi was the foremost politician of her time.