How (can)? làm sao

Làm sao asks "how", and where it goes changes the feel. At the start of a question it often carries surprise, "how on earth": Làm sao anh biết? How did you know?

With để (in order to) after it, it's the practical "how do I …?", for directions, problems and instructions: Làm sao để đi tới chợ Bến Thành? How do I get to Bến Thành market? At the end, after a verb, it asks how something is done: Cái này mở làm sao? How does this open?

Giờ làm sao? or Làm sao bây giờ? means "What do we do now?", when something has gone wrong. And bị làm sao is a set question about someone's health or mood: Em bị làm sao vậy? What's wrong? Are you all right?

You know sao and thế nào for "how" and "what's it like". Làm sao is more about how to manage something. With được at the end, it turns into "how could I possibly", meaning you can't: Làm sao em quên được? How could I ever forget?