you must do
Debes hacer la pregunta correcta.
You must ask the right question.
I'll tell you what you should do.
You must do what I tell you.
Por más ocupado que estés, debes hacer tus tareas.
No matter how busy you are, you must do your homework.
Eso es todo lo que debes hacer.
That's all you have to do.
Debes hacer lo que tú creas justo, por supuesto.
You must do what you think is right, of course.
That's all you have to do.
No debes hacer cosas a medias.
You shouldn't do things halfway.
That's what you should do.