اعراب لم يشرح المعلم الدرس

The teacher did not explain the lesson: “لم” is a negation particle and is based on the consonant. “يشرح” is a present verb conjugated with “لم” and its sign of conjugation is the consonant. “المعلم” is the subject in nominative case with a visible damma at the end. “الدرس” is the object in accusative case with a visible fatha at the end.