I live in To Kwa Wan too
I know that "保護兒童會" next to To Kwa Wan Fire station have playgroups.
U may find the info. through internet easily.
Anyway, I joined TKO 成龍全人教育中心's saturday English playgroup & all kids here are v. happy . (it's a community center in King Lam Estate)
My boy always ask me to play the games that learn from the class together
My sons has attended Tutor Time (Dorset) for almost 10 months now. It's quite goodm 45min in english and 45min in PTH. Both are taught by native speakers. The campus is quite large with both indoor and outdoor playground. You may enroll whatever number of days per week for your kids. My son is now attending 3 days per week which is the lowest per-class rate among all combination.