Transform the following sentence from affirmative to negative without changing the meaning:
This horse is faster than all others.
a) There is no horse faster than this horse.
b) There is no horse as fast as this horse.
c) This horse is faster than no other horse.
d) This horse is as fast as no other horse.

Hint: An affirmative sentence is a positive sentence. A negative sentence has the word “no” in it. The meaning of the sentence should remain the same.

Complete answer:
The correct option is option b because it imparts the same meaning as the meaning given in the sentence. The given sentence says that a horse is faster than all other horses. Option b says that no other horse is as fast as this horse which automatically means that the horse we are talking about is faster than the rest. It is a negative sentence since we are trying to negate the speed of other horses to prove the speed of a particular horse.
Option a is wrong because the sentence given in the option is talking about no horse being faster than the subject horse. This implies that the subject horse is the fastest horse. However, that is not the meaning of the given sentence. The horse is faster than the others but it is not the fastest horse.
Option c is wrong because though the word “no” has been used to make it a negative sentence, the sentence becomes grammatically wrong. The subject of the sentence should be in the negative in a negative sentence. In this option, the subject is still positive (This horse).
Option d is wrong because just like in the previous sentence, the subject of the sentence is positive. Thus it is an affirmative sentence and not a negative one.

Note:
It is a common mistake to get confused between the options a and b. However, the degrees of comparison have to be kept in mind. The meaning of the sentence should also not change during the conversion.