Sentence. 

'I am not a girl" and 'I am not a boy'

You don't really use this phrase but just learn it incase people mistaken you as a boy/girl.

"I am not a girl" ; "Yeoja ani-mida" 여자 아니-미다 

"I am not a boy" : "Namja ani-mida" 남자 아니-미다 

Both are in-formal.
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"Please Don't Do That."

"Please don't do that." ; "Jebal geuleoji maseyo"  제발  그러지  마세요 

Sentence used in....

e.g. Your friend keeps tickling you. So you say, "Unnie/Noona/Hyung/Oppa , jebal geuleoji maseyo!"

This word is formal. You can use it to the people that are older than you. You may also use it to your dongseangs. 

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HEYYYYY SUBBIES.... sorry for not updating for almost 2 months... been busy with my piano exams...AND MY EXAMS ARE OVER!!! yay...lol look forward to my next update yeah?