In Arabic grammar, a sentence containing a مبتدأ (subject) and خبر (predicate) is called a جملة اسمية (nominal sentence). A nominal sentence begins with a noun or pronoun (the مبتدأ), followed by information about it (the خبر). The sentence السماءُ صافيةٌ ("The sky is clear") is a classic example: السماءُ is the مبتدأ (subject, in the nominative case marked by الضمة), and صافيةٌ is the خبر (predicate, also nominative).
The other sentences are جمل فعلية (verbal sentences), which begin with a verb rather than a noun. جلس أحمد على الكرسي ("Ahmad sat on the chair") begins with the verb جلس. ذهب الطالب إلى الفصل ("The student went to the classroom") begins with the verb ذهب. المعلم يشرح الدرس ("The teacher explains the lesson") may appear to start with a noun, but its predicate is a verbal sentence (يشرح الدرس), making it a nominal sentence with a verbal predicate. However, السماءُ صافيةٌ is the purest and most straightforward example of a مبتدأ-خبر structure because both components are clearly nominal.
Exam tip: To identify a مبتدأ and خبر, look for a sentence that starts with a definite noun followed by an indefinite adjective or noun, both in the nominative case (مرفوع). This is the hallmark of the الجملة الاسمية.
