The root of these verbs includes a weak letter (i.e. و ، ا ، ي); therefore, they are irregular (i.e. they have irregular conjugation).
The sick/weak verbs are divided into three types according to the position of the sick letter in the root verb.
|The Irregular Verb (الفِعْلُ المُعْتَل)|
|Naaqis (Defective) verb||Ajwaf (Hollow) verb||Mithaal verb|