Root Weakness

Arabic roots are categorized in many ways. One of them is using the weakness of root letters. In arabic, there are strong and weak letters. The weak letters are Waaw (و) and yaa’ (ي), they are like vowel letters. The strong letters have strong voices, such as Kaaf (ك)and Baa' (ب), just like the consonant letters. Arabic verb that has weak letters in its root is often called weak verb.

Non-Weak Roots

Sound (السالم)

The root doesn't have any weak letters and hamzah.

Examples:

كَتَبَ
Root Letter 3 Root Letter 2 Root Letter 1
ب ت ك
ثَقُلَ
Root Letter 3 Root Letter 2 Root Letter 1
ل ق ث
خَسِرَ
Root Letter 3 Root Letter 2 Root Letter 1
ر س خ
جَامَلَ
Root Letter 3 Root Letter 2 Root Letter 1
ل م ج
اسْتَغْفَرَ
Root Letter 3 Root Letter 2 Root Letter 1
ر ف غ
تَجَمَّعَ
Root Letter 3 Root Letter 2 Root Letter 1
ع م ج

Hamzated (المهموز)

The root has one hamzah, but it doesn't have any weak letter.

Examples:

أَكَلَ
Root Letter 3 Root Letter 2 Root Letter 1
ل ك أ
دَأَبَ
Root Letter 3 Root Letter 2 Root Letter 1
ب أ د
مَلَأَ
Root Letter 3 Root Letter 2 Root Letter 1
أ ل م
تَأَثَّرَ
Root Letter 3 Root Letter 2 Root Letter 1
ر ث أ
تَسَاءَلَ
Root Letter 3 Root Letter 2 Root Letter 1
ل أ س
اِنْكَفَأَ
Root Letter 3 Root Letter 2 Root Letter 1
أ ف ك

Geminate (المضعّف)

The second and the third letter are the same.

Examples:

فَرَّ
Root Letter 3 Root Letter 2 Root Letter 1
ر ر ف
صَبَّ
Root Letter 3 Root Letter 2 Root Letter 1
ب ب ص
ضَجَّ
Root Letter 3 Root Letter 2 Root Letter 1
ج ج ض
اِحْتَجَّ
Root Letter 3 Root Letter 2 Root Letter 1
ج ج ح
تَجَسَّسَ
Root Letter 3 Root Letter 2 Root Letter 1
س س ج
اِنْضَمَّ
Root Letter 3 Root Letter 2 Root Letter 1
م م ض

Weak Roots

Assimilated (المثال)

The first root letter is a weak letter.

Examples:

وَقَفَ
Root Letter 3 Root Letter 2 Root Letter 1
ف ق و
وَضَعَ
Root Letter 3 Root Letter 2 Root Letter 1
ع ض و
يَسِرَ
Root Letter 3 Root Letter 2 Root Letter 1
ر س ي
اِسْتَيْقَظَ
Root Letter 3 Root Letter 2 Root Letter 1
ظ ق ي
تَوَاصَلَ
Root Letter 3 Root Letter 2 Root Letter 1
ل ص و
تَوَازَنَ
Root Letter 3 Root Letter 2 Root Letter 1
ن ز و

Hollow (الأجوف)

The second root letter is a weak letter.

Examples:

قَالَ
Root Letter 3 Root Letter 2 Root Letter 1
ل و ق
حَانَ
Root Letter 3 Root Letter 2 Root Letter 1
ن ي ح
صَارَ
Root Letter 3 Root Letter 2 Root Letter 1
ر ي ص
اِسْتَجَابَ
Root Letter 3 Root Letter 2 Root Letter 1
ب و ج
اِخْتَارَ
Root Letter 3 Root Letter 2 Root Letter 1
ر ي خ
اِسْتَرَاحَ
Root Letter 3 Root Letter 2 Root Letter 1
ح و ر

Defective (الناقص)

The third root letter is a weak letter.

Examples:

ثَنَى
Root Letter 3 Root Letter 2 Root Letter 1
ي ن ث
بَلَا
Root Letter 3 Root Letter 2 Root Letter 1
و ل ب
رَجَا
Root Letter 3 Root Letter 2 Root Letter 1
و ج ر
أَدْنَى
Root Letter 3 Root Letter 2 Root Letter 1
و ن د
اِشْتَرَى
Root Letter 3 Root Letter 2 Root Letter 1
ي ر ش
أَعْمَى
Root Letter 3 Root Letter 2 Root Letter 1
ي م ع

Doubly Weak (اللفيف)

It has 2 weak letters or a weak letter and a hamzah.

Examples:

دَوَى
Root Letter 3 Root Letter 2 Root Letter 1
ي و د
وَلِيَ
Root Letter 3 Root Letter 2 Root Letter 1
ي ل و
عَيَّ
Root Letter 3 Root Letter 2 Root Letter 1
ي ي ع
اِسْتَوْلَى
Root Letter 3 Root Letter 2 Root Letter 1
ي ل و
اِسْتَحْيَا
Root Letter 3 Root Letter 2 Root Letter 1
أ و س

Exceptions

Roots with 4 letters (quadrilateral verbs) may not be categorized in this way.