Defective roots end in a weak letter (و or ي). When creating verbal nouns (masdars) for derived forms of these roots, the standard patterns adjust slightly.
Form II
For Form II verbs, the standard verbal noun pattern is تفعيل. For defective roots, this changes to تفعلة, dropping the long ي and adding a taa marbuta (ة) at the end.
For example, the verb سمى (to name) forms the verbal noun تسمية (naming). The verb ضحى (to sacrifice) forms تضحية (sacrifice).
| Did you name the new project? | هل سميتم المشروع الجديد؟hal sammaytumu-l-mashrûa-l-jadîd? |
| Naming the new baby was very easy. | كانت تسمية الطفل الجديد سهلة جدا.kânat tasmiyatu t-tifli l-jadîdi sahlatan jiddan |
| The doctors sacrificed their time for the patients. | ضحى الأطباء بوقتهم للمرضى.dahha al-atibba'u biwaqtihim lilmarda. |
| We thank you for this big sacrifice. | نشكرك على هذه التضحية الكبيرة.nashkuruka 'alâ hâdhihi t-tadhiyati l-kabîra |
Form III
The standard verbal noun pattern for Form III is مفاعلة. When the root is defective, the final weak letter becomes a regular alif (ا) before the taa marbuta (ة), resulting in the ending اة.
For example, the verb نادى (to call) forms the verbal noun مناداة (calling).
| Why did you call the waiter a lot? | لماذا ناديتم النادل كثيرا؟limâdhâ nâdaytumu n-nâdila kathîran? |
| They heard the calling of the poor man. | سمعوا مناداة الرجل الفقير.sami'oo munâdâta r-rajuli l-faqeer |
Form IV
The standard verbal noun pattern for Form IV is إفعال. When the root is defective, the final weak letter becomes a hamza (ء) on the line, creating the ending اء.
For example, the verb أهدى (to gift) forms إهداء (gifting), and the verb أعطى (to give) forms إعطاء (giving).
| Fatima gifted a flower to her friend. | أهدت فاطمة زهرة لصديقتها.ahdat fâtimatu zahratan lisadîqatihâ |
| Gifting the book to the family is very beautiful. | إهداء الكتاب للعائلة جميل جدا.ihdâ'u al-kitâbi lil-'â'ilati jamîlun jiddan |
| Giving the poor money is a charitable act. | إعطاء الفقراء مالا عمل خيري.itâ'u al-fuqarâ'i mâlan amalun khayriyyun |