the difference between Koreans and Chinese in the eyes of foreigners

(1)If you live in an abnormal foreign country, you must learn the mother tongue of that country. vs. Never mind.
(2)What Alberto saw.
(3)Big Difference Between China and Korea
(4)If you live in a foreign country, you will learn your native language.
(5)must learn vs. Never mind.
(6)Chinese people…
(7)Alberto speaks Chinese when he meets a foreigner who studies in China.
(8)If you live abroad, you must learn the native language of that country. vs. Never mind.
(9)If you don’t understand Alberto’s Chinese study fee, speak in Chinese.
(10)must learn vs. Never mind.
(11)I see
(12)I’ll try it and if it doesn’t work, English.
(13)Alberto speaks English to Westerners in Korea.
(14)It’s not a must-learn vs.
(15)English-speaking
(16)a comfortable environment for foreigners
(17)You’re going to learn vs. Never mind.
(18)If you live in a foreign country, you can learn your native language.
(19)I need to learn Korean.
(20)You may not feel the need.