صرف/SARAF/SORF: Pelajaran 1.1 : الفعل الثلاثى المجرد (English Version)

The Second Category of Verbs
With regard to the root letters (الحروف الأصلية) of a verb, they are of two types:

Each of these two types is further divided into two categories:
(1) (مجرد) – the (الماضي) consists of root letters only, without any extra letters.
(2) (مزيد فيه) – the (الماضي) has root letters plus extra letters.

This results in the following four categories:

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Rujukan:
Maulana Ebrahim Muhammad. 2006. FROM THE TREASURES OF ARABIC MARPHOLOGY. Camperdown South Africa: Madrasah In’amiyyah.