87. On and in 

Use on when the meaning is clearly 'on top of'. Example: 'on a table'. Use in when 'on top of' is not appropriate. 

• Incorrect: He rides in a cycle. 

• Correct: He rides on a cycle. 

• Incorrect: He rides on a car. 

• Correct: He rides in a car. 

• Incorrect: He sat on a tree. 

• Correct: He sat in a tree.