In Arabic grammar, sentences are classified into two types based on what they begin with:
الجملة الاسمية (nominal sentence): begins with a noun (اسم), consisting of a subject (مبتدأ) and a predicate (خبر).
الجملة الفعلية (verbal sentence): begins with a verb (فعل), typically followed by a subject (فاعل) and possibly an object.
Examining the options:
السماء صافية - begins with the noun السماء: nominal sentence
ذهب التلميذُ إلى الفصل - begins with the verb ذهب (went): verbal sentence
المدرسة جميلة - begins with the noun المدرسة: nominal sentence
الطالبُ متفوق - begins with the noun الطالبُ: nominal sentence
The only verbal sentence (جملة فعلية) is "ذهب التلميذُ إلى الفصل" (the student went to the classroom), where ذهب is a past-tense verb (فعل ماض), التلميذُ is the subject (فاعل), and إلى الفصل is a prepositional phrase (جار ومجرور).
