Sir is this the right subway for Chinatown?
Yes, you get off at Brown Street, cross it to reach Green Street, walk along Green Street and turn into Canal Street at the first crossing. Chinatown is right there.
Shall I take the expresser local train?
Take the express, the price is the same, but it saves you a lot of time. The local train stops at every station.
How much is the fair?
$1 for the entire line. You should pay 30 cents to get off here.