Is it appropriate to start teaching Indian children English as early as 4 or 5 years even though the family members of such children do not know English?

edit

I'm no expert, but research suggests that in a child's development, the success and proficiency in it's L1 is related to outcomes for further languages he or she learns. Someone has to have a high level of proficiency in the mother tongue, in order to achieve the same level in a foreign language. Learning the home language strongly benefits this process.

In the Nerherlands, we have seen something similar with North African and Turkish migrant children, who didn't progress in their mother tongues, as Dutch was considered more useful and/or important from a social perspective. This meant that their parents tried to learn Dutch at the same pace as their children, with limited success: both parents and children were not sufficiently aware of nuances and grammar in Dutch. They spoke a kind of faulty Dutch at home, that might end up causing career problems, rather than benefits.