bao lâu

Meaning

1. how long

   question word

   For a length of time; to ask at what time something happens, use mấy giờ.

   • Anh ở Việt Nam bao lâu rồi?

     How long have you been in Vietnam?

   • Đi xe buýt mất bao lâu?

     How long does it take by bus?

   Grammar: How long? bao lâu after the verb