Don't have any experience with it personally, but I know some people who grew up trilingual. The might have mixed the languages up a little at an early age, but not for long. I would at least try to speak both languages so that your kids at least understand them both. If they don't want to speak Chinese...well then you can't force them. I once had a Japanese teacher, who was complaining about her son, not wanting to talk Japanese. You just can't force your kids, but if you live in Taiwan, you can just make them play with Chinese speaking kids or send them over to the grandparents, who I guess don't speak English....I'm sure they will be grateful later.