Go to college? I know that most courses in college are in English, including teachers' lectures, handouts and exams, as long as your English is good enough. Most mainland students have no problem reading traditional Chinese characters, because habit problems may be difficult to write. Cantonese in Hong Kong is less influenced by the mainland. I feel that Cantonese in Hong Kong is more difficult to understand than Cantonese in Guangzhou and Shenzhen. I can only read less than 30% of newspapers and magazines in Hong Kong except pictures. You must learn Cantonese, and you can learn it quickly in that language environment. Mandarin is not popular there, ie much better after free travel. During the morning tea, I spoke Mandarin with my uncles and aunts who were pushing cars to sell breakfast. They have no idea what I'm talking about.