Foundation of Formation of adjective 

Adjective is very important part of English grammar. They can be formed by noun and verb also.

From noun & verb

From noun

Some nouns can transform into adjectives

.1. Some adjectives can be form from nouns by adding the proper suffixes.

Eg. I. Power + full-- powerful

       2. Gold+ en  --- golden

       3. Glory+ ous --- glorious

       4. Mission + ary -- missionary

2. Some adjectives can be formed from verbs by adding the proper suffixes.

Eg

1. Need + less = needless

2. Need+ y = needy

3. Negate + ve  = negative

4. Neglect + full = neglectful

3. Some adjectives can be formed from nouns by dropping the proper suffixes.

Eg.

1. Usefulness - ness = useful

2. Difficulty-y = difficult

3. Bravery - y = brave

4. Cruelty -y = cruel

4. Some adjectives can be formed from verbs by dropping the suffix --- en.

Eg.

1. Quieten- en = quiet

2. Sadden - en = sad

5. Some adjectives can be formed from verbs by dropping the prefixes.

Eg.

1. Belittle - be = little

2. Be fool- be = fool

3. Enlarge - en = large

4. Enrich - en = rich

6. Adjectives can be formed from adverbs by dropping the suffix --- ly.

Eg.

1. Slowly - ly = slow

2. Really - ly = real

3. Beautifully - ly = beautiful

4. Carefully - ly = careful

The table of adjective formation 

Some more examples : 

 From verbs

Verb                        Adjective

1. Attend               attentive / attendant

2. Concentrate      concentrative

3. Dust                  dusty

4. Continue          continuous

5. Lower                low

6. honorable       honor

7. Play                    playful

8. Sleep                  sleepy

9. Manage          manageable

10. Need           needy

Form nouns

Noun                 Adjective

1.  Ability         able

2. Air               airy

3. Sun            sunny

4. Bravery       brave

5. Centre          central

6. Cloud          cloudy

7. Anxiety        anxious

8. Comfort      comfortable

9. Depth             deep

10. East           eastern

11. Emotion    emotional

12. Fame         famous

13. Occasion    occasional

14. Might         mighty

15 nature          natural

16. Safety            safe

17. Pain           painful

18. Poet          poetic

19. Rain             rainy

20. Wonder      wonderful

From Adverbs

Adverb                  adjectives

1. Abruptly         abrupt

2. Angrily           angry

3. Annually        annual

4. Clearly           clear

5. Bitterly         bitter

6. Boldly           bold

7.  Anxiously    anxious

8. deeply           deep

9. Differently     different

10. Eagerly         eager

11. Cleverly         clearly

12. Easily           easy

13. Excitedly      excited

14. Quickly         quick

15. Happily         happy

16. Innocently     innocent

17. Logically         logical

18. Merrily         merry

19. Neatly      neat

20. Painfully    painful