Thank you for your input. The one person = one language is echoed by eande and wooyi too, so maybe I'll try that. My mom takes care of him half of the week in

Thank you for your input. The one person = one language is echoed by eande and wooyi too, so maybe I'll try that. My mom takes care of him half of the week in the day time and speaks Chinese to him, so that's why I was trying to speak some English to him since he doesn't get much exposure to English (no daycare yet). I may be exaggerating a bit on the 40% though, it's probably less than that, mostly just on some vocabulary that doesn't come out naturally in Chinese for me. Playing memory game is a good idea, we haven't done too much of that.