Stopping and Starting with "Al" — Solar and Lunar Letters

Definition of "Al":
"Al" is the definite article in Arabic and the Quran. It consists of a connecting alif + laam.

Solar Letters (14 letters):
ت ث د ذ ر ز س ش ص ض ط ظ ل ن — when a word begins with one of them after "al," the laam merges into it: "al-shams" = "ash-shams."

Lunar Letters (14 letters):
أ ب ج ح خ ع غ ف ق ك م و ه ي — the laam appears clearly and does not merge: "al-qamar."

Stopping on a word beginning with "Al":
When stopping, the solar/lunar distinction does not appear — both are stopped on by giving sukoon to the final letter.

Starting with "Al":
Starting begins with a connecting hamza: "al-hamdu" starts with "a" after a stop. If following a voweled letter (continuing), the hamza drops and solar merging or lunar clarity applies.

Mnemonic:
The mnemonic "Tib thumma sil rahiman tafuz dhif dha niam da suu-a thannin zur sharifan lil-karam" — its initial letters are the solar letters.