Rules of Use of Adjectives: English Grammar Series

1. Progressive comparisons - The comparative from of an adjective can also be sued to describe a characteristic which is becoming progressively more pronounced.

Examples - 1) The waves are growing rougher and rougher. 
2) The sounds became fainter and fainter. 
Examples - 1) The noise is getting louder and lounder. 
2) The lights got brighter and brighter. 

2. While comparing an object with others, it is necessary to exclude it from the Comparison . 
Examples - a) Iron is harder than any metal. (Incorrect) 
Iron is harder than any other metal.(Correct) 
b) This building is larger than any building in the town . ( Incorrect) 
This building is larger than any other building in the town (Correct) 

3. Town comparative adjectives are not normally used in a sentence. 
Examples - (a) He is more wiser than you (Incorrect) 
He is wiser than you. (Correct) 
(b) I am comparatively better today. (Incorrect) 
I am better today. (Correct) 
I am comparatively well today (Correct) 
If one adjective is in Comparative Degree the other should be in positive. 
We should also not use any Comparative Degree adjective with the word ‘compartively. 
But we can use rather with the adjective of comparative Degree. 
Example - She is rather better today. 

4. Some Comparative Degree Adjectives, ending in ‘or’ are followed by the preposition ‘to’ instead of ‘than’. Such adjectives are; senior, junior, posterior, superior, inferionr, anterior. All these adjectives are borrowed from Latin. Likewise; Elder, prefer and preferable also take preposition ‘to’ with them. 
Example – a. He is superior to me. 
b. She is junior to me. 
c. Ram is senior to Shyam. 
d. He came prior to me. 
Major, minor, exterior, interior, outer, lower, ulterior, supper, former, inner are some words that resemble with comparative Degree Adjectives are no comparatives. 

5. When we compare two qualities in the same person or thing we should not use comparatives in ‘er’, instead we should use ‘more’. 
Examples – a. Ram is more strong than intelligent. (not stronger) 
b. She is more clever than intelligent. ( not cleverer) 

6. Superlative forms of adjectives The superlative form of an adjective is used to describe something which possesses a characteristic in the greatest degree. 
Examples – a. Dhiraj is the youngest boy in our class. 
b. She is the best actress I have ever seen. 

7. The superlative form preceded by ‘the’ The superlative forms of adjectives are usually preceded by the, and followed by the nouns they modify. 
Examples – a. Shyam is the tallest boy in the class. 
b. Nisha is the fastest runner of the team. 

8. The comparison of one or more things with a group When one or more things are compared with a group to which they do not belong , the comparative form of an adjective is normally used. 
Example - The girls are cleverer than the boys. The girls are being compared with the boys, a group to which they do not belong. Therefore, the comparative form cleverer is used. 
In contrast, when one or more things are compared with members of a group to which they belong, the superlative form of an adjective is normally used. 
Example - Ashok is the youngest of all the boys in the class. 
In this example, Ashok is being compared with members of the group identified as all the boys in the class. This is a group to which he belongs. Therefore, the superlative form youngest is used. 

9. Logical Comparison While making comparisons, care must be taken, particularly in formal English, to ensure that the comparisons are logical, and that the appropriate objects are in fact being compared. 
Example Life in the country is different from the city. (Incorrect) 
The sentence is logically incorrect, because it compares life in the country to the city. In order to be logically correct, the sentence must be changed so that similar types of things are being compared. 
Example Life in the country is different from life in the city. (Correct) 
This sentence is logically correct, since it compares Life in the country to life in the city. 

10. Comparative Degree of adjectives is used for the comparison of two, for more than two we should use the superlative. Likewise, we should not use the superlative for comparing two objects. 
Examples – a. Which is better: tea, coffee or milk? (Incorrect) 
Which is the best; tea, coffee of milk? (Correct) 
b. He is the best of the two students. (Incorrect) 
He is the better of the two students. (Correct) 

11. Normally two superlatives are not used in a sentence. 
Example - a. He is the most strongest of all. (Incorrect) 
He is the strongest of all. (Correct) 

12. We should also not use ‘other’ or ‘else’ with superlatives.
Examples – a. She is the most beautiful of all girls. (not all other girls)
b. He is the strongest of all students. (not all other students)

13. When more than one adjectives are connected with ‘and’, they should be either in Comparative or in Superlative Degree.
Example – a. Ram is wiser and stronger than Shyam. (Correct)
b. Ram is wise and sstronger than Shyam. (Incorrect)

14. Some adjectives expressing qualities of highest order, their extreme meanings can’t be compared. Such adjectives are absolute, perfect, full, complete, entire, whole, chief, extreme, unique, universal, circular, square, round, ideal, flat, impossible etc.
A thing can’t be more round, more square.
Though we can find using : full, fuller, fullest and perfect, more perfect, most perfect and also most impossible , by some writers.

15. Note the structure of the following sentences .
One of …………if not………….. Superlative……….
Examples – a. He is one of the greatest writers, if not the greatest writer.
b. This is one of the largest buildings, if not the largest in the world.
Use plural noun in first part and singular noun in second part of the sentence.
One of the + Superlative + Plural noun …….If not the +Superlative + Singular noun.

16. Note the following structure also.
Examples – a. She runs as fast as, if not faster than Shyam.
b. He is as good as if not better than you.
c. The house is as large as if not larger than that.