Born and raised in Hong Kong speaking Cantonese natively. Went to college in the United States and subsequently lived and worked in Silicon Valley for over 10years.Englishwastheprimarylanguageduringthosecollegeandworkingyears.IthenrelocatedtoShanghaiandspentmorethan10 years in the mainland before moving back to Hong Kong. I used Putonghua in daily life and professionally at work. I got a college degree in chemical engineering and computer science, and a master degree in computer science. I can tutor science subjects and math besides English.