andymom
your son is only 16 months and can actively use 500 words and make short sentences already?! :shock: my daughter is the same age and she can possibly speak 10-15 short words. so if what you've observed is true, then i wouldn't worry about his english abilities! by the time he's ready to attend kindergarten/school, he'll be perfectly fine.
my daughter is exposed to 4 languages, and hence her english acquisition is delayed. oh well - i'll go to playgroups with her, let her play with other kids and really hope for the best till it's time for a kg interview...