Anh hỏi đường được không?

Why it works

`được không?` at the end asks permission rather than assuming it, which is what turns a demand into a request. Helping a lost foreigner is something most Vietnamese people will stop for, which is exactly why the question has to be real: it spends a goodwill that is not yours to fake. If she looks older than you, it is `Em hỏi đường được không chị?` and the roles swap.

Careful

⚠If you have Google Maps open in your hand, do not ask for directions. She will see the screen and the whole thing becomes a lie she caught you in. And when she has answered, thank her and go the way she pointed, even if you knew it: the exchange ends when the information ends, unless she extends it herself.

What she says back

• Anh đi thẳng rồi quẹo phảiCould go either way

  Go straight then turn right

  → Repeat it back to check you got it. That repetition is a legitimate second exchange.

• Em cũng đi hướng đóGreen light

  I'm going that way too

  → She offered. Walk together, at her pace, and ask what's worth seeing on the way.

• Em không rành khu nàyThat's a no

  I don't know this area

  → `Dạ, cảm ơn em` and ask someone else. Do not turn it into a conversation about where she is from.