What is Apposition?

Apposition is a word or group of words which adds extra information to a noun or pronoun. The appositive does not change the meaning of the sentence in case it is removed from the sentence. Look at the pair of examples (The first one of the pair has no appositive.). 

• You should study hard. 
• You students should study hard. ('student' is an appositive.)

• Thida is very smart. ('student' is an appositive.)
• Thida, our team leader, is very smart. ('our team leader' is an appositive.)

Be careful!

• You are students should study hard. 

It is a wrong sentence because you have two main verbs in this sentence. Instead, you can make it an adjective clause.

•  You who are students should study hard.