At what age should a child start school, mine has turned 2 month old now.

Any International School around Rom Klao-Suvarnabhumi Road accepting 2 month old boy yet? I'm concerned due to his mommy & grand ma speak to him in Vietnamese and I can only speak English-Thai. By Feb 2019, they are bringing him to Vietnam for TET's festival to my wife's family side and I won't come along.