Learning a language by memorizing bare lists is boring and difficult. Is your son able to hold a conversation in simple Chinese? That would be much more meaningful. I hope he can keep up his interest, preferably with your encouragement.
You can find occasional posts about learning Chinese here: #learnchinese
Thanks for the kind words and recommendation.. well he said its not easy, but i guess you are right its boring by memorizing bare lists and I believe with his interest on it heβll be able to speak Mandarin in the future πππ»
Try to make friends with Chinese people who have kids and don't speak English or Tagalog well. Language exchanges are lots of fun. No teaching: just do fun things together (sports, cooking, games) first in one language, then in the other. Example: Mon, Wed and Fri in Chinese, Tue, Thu and Sat in English/Tagalog.