<p>How do you use the following three sentences? What is the difference?</p><p><br></p><ol><li>If I <strong>failed</strong> the exam, what would my parents say?</li><li>If I <strong>should fail</strong> the exam, what would my parents say?</li><li>If I <strong>were to fail</strong> the exam, what would my parents say?</li></ol><p><br></p><p>Thank you.</p>