Affirmative to Negative

Affirmative: The coffee is hot.
Negative: The coffee is not cold.

Affirmative: The movie was interesting.
Negative: The movie was not boring.

Affirmative: She will arrive soon.
Negative: She will not depart soon.

Affirmative: The answer is correct.
Negative: The answer is not wrong.

This is true for sentences with Be Verbs, sentences that have Auxiliary Verbs (e.g. They have done well. She is reading.) and sentences with Modal Verbs (can, will, should, might, etc.). 

2. Present Simple and Past Simple

Affirmative: Our team looks confident.
Negative: Our team does not look unconfident.

Affirmative: They answer correctly.
Negative: They do not answer incorrectly.

We use the auxiliary verb did in the past simple. 

Affirmative: I stood first.
Negative: I did not stand last.

Affirmative: She opened the door.
Negative: She did not close the door.

Exercise for Practice

Change the following sentences into negative without changing the meaning.

1. They sing beautifully.
2. I played carefully.
3. He explained the lesson clearly.
4. I studied attentively.
5. Anger is a vice. 
6. He is very sincere.  
7. Man is mortal. 
8. We should regard their sacrifice. 
9. Students will always remember their school life. 
10. We go to school regularly. 
11. The idle always lag behind. 
12. I was very glad. 
13. Tree plantation is a noble task. 
14. Mobile phone is an amazing invention of modern science. 
15. Frugality is a good habit. 
16. Birds are a beautiful gift of nature. 
17. The students are very obedient. 
18. A boat journey is very enjoyable. 
19. He was unmarried. 
20. The village people were quarrelsome. 
21. She was very kind to the needy and the ill-fated. 
22. The market was far from his house.  
23. Its functions are smooth and rapid.  
24. Computer is a blessing on earth.  
25. Her parents liked her very much. 
26. It is a mega project. 
27. My friend is always punctual. 
28. In fact, a moonlit night is very pleasant. 
29. Initially the questions may seem difficult. 
30. Our winter is dry and rainless. 

Forming Negative Sentences without "Not"

Do not add "not" if the antonym itself is a negative word (e. g. never, no, none, nobody, no one).

Here are some examples. Look at them carefully and then do the exercise that follows. 

Only/ None but (People or Divine Beings)

Affirmative: Only the winner will receive a prize.
Negative: None but the winner will receive a prize.

Affirmative: Only God knows the truth.
Negative: None but God knows the truth.

Only/ Nothing but (Things)

Affirmative: Only the birds were singing.
Negative: Nothing but the birds were singing.

Affirmative: We ate only bread.
Negative: We ate nothing but bread.

Only/ Not more than (Numbers)

Affirmative: I waited for only ten minutes.
Negative:  I waited for not more than ten minutes.

Affirmative: I have only 10 pens.
Negative:  I have not more than 10 pens.

Only/ Never but (Time)

Affirmative: The cuckoo sings only in the spring.
Negative: The cuckoo sings never but in the spring.

Affirmative: You can see a rainbow only when the sky is cloudy.
Negative: You can see a rainbow never but when the sky is cloudy.

Only/ Nowhere but (Place)

Affirmative: Fishes can live only in water.
Negative: Fishes can live nowhere but in water.

Affirmative: She lived only in her village.
Negative: She lived nowhere but in her village.

Alone / None but

Affirmative: She alone knew the truth.
Negative: None but she knew the truth.

Affirmative: The king alone could enter the sacred chamber.
Negative: None but the king could enter the sacred chamber.

Rewrite each affirmative sentence as a negative sentence based on the given rules. Do not write the answers.

1. Cats can live only in warm places.
2. The old clock chimes only at midnight.
3. Only the brave face such dangers.
4. We heard only whispers in the dark.
5. She bought only five dresses.
6. She alone managed the entire event.
7. She works only in her studio.
8. Flowers bloom only in spring.
9. Only a true friend stands by you in trouble.
10. She ate only fruits for breakfast.
11. The meeting lasted only 15 minutes.
12. The knight alone fought the fierce dragon.
13. Birds can survive only in natural habitats.
14. The theatre opens only in the evening.
15. Only the wise understand the meaning of life.
16. The room contained only old books.
17. I have only two coins in my pocket.
18. The queen alone ruled the kingdom for decades.
19. Tigers are found only in dense forests.
20. The owl hoots only at night.
21. Only the teacher knows the correct answer.
22. He carried only essentials on his trip.
23. He waited for only 30 seconds.
24. He alone completed the difficult task.
25. They travel only to mountain regions.
26. They meet only on weekends.
27. Only the artist painted this masterpiece.
28. We found only broken toys in the attic.
29. The garden has only three apple trees.
30. The soldier alone faced the enemy.

Superlative:  Use "no other ... as ... as"