Baekhyun: Introducing You're next teacher D.O!! 

Kyungsoo: YA! BYUN BAEHYUN!

Baekhyun: Yes? *Innocent face* 
Kyungsoo: Why do you keep bullying me?! *Hits baekhun* 

Baekhyun: Ya! I'm you're hyung. 
Kyungsoo: Hyung~ *Pouts* 
Baekhyun : Fine Fine. See you in our lesson Oranges.*Fabulously leaves*

Kyungsoo: Oranges, Don't mind him and please call me Kyungsoo oppa. 
Oranges: Nehhh~ 

Remember your topic particle? 

'는' 
Well the particle 은 has the same exact function butonly one of them can be used in a given function.

는 &은 are both topic particles 
But

Kai는 학생이에요 is correct

Kai은 학생이에요 is wrong. 

English analogy.
a boy (you use 'a')
but 
an elephant (you use 'an')

'A' before a consonant 
'An' before a vowel.
 

This is similar to Korean. 
는 after a vowel

은 after a consonant 

D.O: Is everything starting to get harder? Don't worry oranges you will start to get familiar with this.

Example One. 
Kai는 학생이에요

Notice Kai ends with a vowel? so we use the particle 는

Example Two

Chen은 학생이에요

Notice CheN ends with a consonant? So we use the particle 은 

Example Three

저는 학생이에요

Notice 저(Ja) ends with a vowel? So we use the particle 는

 

PRONOUNCITATION RULES! 

Chen은 is written like that but pronounced like "Chen는"

ONLY PRONOUNCED BUT NOT WRITTEN!

Always remember 

는 after a vowel

은 after a consonant 

I learnt it easier by thinking that oppistes attract. 

Example 
Chen은 (The N (Consonant) is attracted to an oppisite which is a vowel)

Kai는 (The I(vowel) is attracted to an oppisite which is a consonant) 

Does it sound weird? Do you understand?

You can use any method to help you remember or use mine. 

Kyungsoo: BYE ORANGES!!DON'T FORGET WHAT I HAVE THAUGHT YOU!