العلاقة بين الوزن الثاني "فعَّل" والخامس "تفعَّل" ،، What is the relation between Form II and V

- Form 2 - فعّل (fa33ala)
Built on form 1 by doubling the middle radical of the form 1 verb (adding a shadda to it)
Often is a causative version of the form 1 verb
خرج (xaraja) means "to go out"; خرّج (xarraja) means "to make (s.o.) go out; to graduate (s.o.)"
Often an intensive version of the form 1 verb (especially if the form 1 verb is transitive)
جمع (jama3a) means "to collect, gather"; جمّع (jamma3a) means "to amass, to accummulate".

- Form 5 - تفعّل (tafa33ala)
Built on form 2 by adding the prefix تـ to the form 2 verb
Often a reflexive version of the form 2 verb
خرّج (xarraja) means "to graduate (s.o.)"; تخرج (taxarraja) means "to graduate" (Note: form 5 is usually intransitive)
Sometimes an intensive version of a form 1 verb
جمع (jama3a) means "to collect, gather"; تجمّع (tajamma3a) means "to congregate, to flock together".