Conditional in Arabic grammar involves combining two clauses, where the fulfillment of the condition in the first clause determines the occurrence of the event in the second clause. Conditional sentences in Arabic can be constructed using particles such as إِنْ (if), لَوْ (if), مَتى (when), and لَوْلا (if not). Learning conditional structures is essential for mastering the Arabic language, as they enable learners to express thoughts, desires, and possibilities in various situations.