Sun and Moon Letters

لام التعريف/ اَلْمُعَرِّفُ بِاللَّامِ – word with the definite article ال in the beginning.

ISM

اَلْحُرُوفُ الشَّمْسِيِّةُ / Sun Letters

When ال appears before an إِسْمٌ which begins with اَلْحُرُوفُ الشَّمْسِيِّةُ then the ل of ال must not be pronounced. The ل of ال will not get a sukoon. Instead the حَرْفٌ شَمْسِيٌّ (sun letter) will get a shaddah ـّ .

ت ث د ذ ر ز س ش ص ض ط ظ ل ن  – اَلْحُرُوفُ الشَّمْسِيِّةُ

e.g. اَلشَّمْسُ The sun, اَلشَّجَرَةُ The tree

اَلْحُرُوفُ الْقَمَرِيَّةُ / Moon Letters

When ال appears before an إِسْمٌ which begins with اَلْحُرُوفُ الْقَمَرِيَّةُ (The moon letters) then the ل of ال will get a sukoon and will be pronounced. Instead the حَرْفٌ قَمَرِيٌّ (moon letter)will not get a tashdeed ـّ .

ج ح خ ع غ ف ق ك م ب ي و ه ء – اَلْحُرُوفُ الْقَمَرِيَّةُ

e.g. اَلْقَمَرُ The moon, اَلْمُسْلِمُ The muslim 

Note an  إِسْمٌ can never have ـٌ ـً ـٍ) تَنْوِيْنٌ) and ال at the same time.