Change the narration: The teacher says, "If you work hard, you will pass the test".

The narration can be changed to "The teacher said that if I worked hard, I would pass the test" (indirect speech) or "The teacher said to the students, 'If you work hard, you will pass the test'" (if the teacher is still addressing the students directly). In indirect speech, the tense shifts from present to past, and the pronoun "you" changes to "I" or "they".