Root Letters and Added Letters

Derived Trilateral (with Hamzah) - Bab 2: Istif'aal (Istinsar)

In اِسْتَنْصَرَ, separate the root from the added prefix.

LettersType
ن، ص، رOriginal root letters
ا، س، تAdded letters

So the root remains ن-ص-ر, while اِسْتَـ creates the Istif'aal pattern.