Moon and Sun Letters

• In Arabic the ال prefix comes before nouns to make them definite.
• The ل in this prefix, sometimes forms a shadda with the letter after it and sometimes is recited openly with a jazm.
• If any of these letters ء هـ ب غ ح ج ك و خ ف ع ق ي م come after ل then it is recited openly with a jazm. These letters are called qamari, or moon, letters. The name comes from the word for moon اَلْقَمَرُ.
• If any other letter besides the ones listed above comes after lam, lam forms a shadda with the letter after it. These letter are called shamsi, or sun, letters. The name comes from the word for sun اَلشَّمْسُ for which this rule applies.