It is not an easy task. (Affirmative Sentence)

Everybody wants to make a good result in the examination. (Interrogative Sentence) = Who doesn't want to make a good result in the examination? 

Being industrious, every student can make a good result. (Negative Sentence) = Without being industrious, no student can make a good result. 

The idle always lag behind. (Complex Sentence) = Those who are idle always lag behind. 

They must work hard so that they can prosper in life. (Simple Sentence) = They must work hard to prosper in life. 

Girls can work as much as boys. (Comparative Degree) = Girls cannot work less than boys. 

Students should also observe the rules of health. (Passive Voice) = The rules of health should also be observed by students.