My son is 3.5yrs old and he doesn't like to speak Mandarin at home. Even when I speak in Mandarin to him, he will reply in English. How do I get him to speak more? He speaks Mandarin to his Chinese teacher in school.

I know a lot of people who run into this problem. It is really difficult - I think consistency is key. Firstly, it's important to be firm and clear in your expectations (and that should extend to all the adults in the family, not just mum) - at home, we speak Mandarin. I have friends that have gone so far as to completely ignore their child unless they use Mandarin. A bit harsh, in my opinion, but their kids grew up speaking perfect Mandarin - so well worth the effort. Another useful strategy might be to get him interested in Chinese cartoons. It's an easy and relatively pain free way to learn.