My son went through the local stream of KCIS. Our goal from the outset, was for our son to be fluent in spoken Mandarin and competent in writing and reading (traditional) Chinese, all of which our son has attained. However it is not easy - my wife is Taiwanese and without a Chinese writer and speaker at home it would have been very difficult. The local curriculum is intense and needs discipline and perseverance from both the child and the parents - the kindergarten focusses on vocabulary while there is a notable shift in emphasis to writing and reading in Primary. The teachers are very good, professional and approachable, and are flexible to assist any child needing help. My son is Eurasian with English spoken at home so his vocab and written were never a issue.