In this post, I explain the difference between 2 verb forms: form II (فعَّلَ) and form V (تفعَّلَ). Form II is always transitive, i.e. it must take an object at all times, so the sentence in which a form II verb is used must have a subject and an object, e.g.

كسّر الولد الزجاج.

“The boy broke the glass.”

علّمني أبي القرآن.

“My father taught me the Qur’an.”

Form V is always intransitive, i.e. it never takes an object, so the sentence in which a form V verb is used has only a subject, e.g.

تكسّر الزجاج.

“The glass broke.”

تعلّمت القرآن.

“I learned the Qur’an.”

Form V verbs have a range of meanings implied in them; some verbs imply that the action is done by the subject, e.g.

تعلّم (learned) =

تكلّم = (spoke)

Some verbs imply that the action is spontaneous, e.g.

تكسّر = (broke)

تطوّر = (developed/evolved)

Some verbs imply that the subject is irrelevant or unknown, and in this case we translate it into passive in English, e.g.

تشرّف = (was honored)

تعزّز = (was strengthened)