Key Takeaways
- The Arabic definite article "al-" behaves differently depending on which letter follows it, and this is what Lam Shamsiya and Lam Qamariya describe.
- With Lam Qamariya, moon letters, the lam is written and pronounced clearly, with no change to the following letter.
- With Lam Shamsiya, sun letters, the lam is written but stays silent, and the following letter is doubled instead.
- Arabic has exactly 14 sun letters and 14 moon letters, together covering the full alphabet.
- Recognising the two groups becomes automatic with practice, and a teacher's correction speeds this up considerably.
The Arabic definite article "al-" (ال) is pronounced differently depending on which letter follows it. With moon letters, the lam is voiced clearly. With sun letters, the lam stays silent and the following letter is doubled instead. Arabic has exactly 14 of each.
What This Rule Describes
In Arabic, the definite article "al-" is added to the front of nouns, similar to "the" in English. What changes is how that lam is actually pronounced, and this depends entirely on the letter that comes right after it. This isn't a rare exception. It affects an enormous number of everyday words, which is why it's one of the earlier rules covered once a student starts reading connected text rather than individual letters.
Lam Qamariya: Moon Letters
With Lam Qamariya, the lam is written and pronounced exactly as it appears, with a clear sukoon, and the letter that follows is unaffected. A well known example is القَمَرُ (al-qamar, "the moon"), where the "l" sound is clearly heard.
Lam Shamsiya: Sun Letters
With Lam Shamsiya, the lam is still written in the text, but it isn't pronounced. Instead, the letter immediately following it is doubled, carrying a shaddah, which effectively absorbs the lam's sound into itself. A well known example is الشَّمْسُ (ash-shams, "the sun"), where you hear "ash-shams," not "al-shams."
This is where the naming comes from: shams means sun, and qamar means moon, and each rule is named after its own well known example word.
The Full Letter Lists
The 28 letters of the Arabic alphabet split evenly between the two categories.
| Type | Letters |
|---|---|
| Moon letters (Qamariya) | ا ب ج ح خ ع غ ف ق ك م و ه ي |
| Sun letters (Shamsiya) | ت ث د ذ ر ز س ش ص ض ط ظ ل ن |
Every Arabic letter falls into exactly one of these two groups, with no overlap.
Why It's Called "Sun" and "Moon"
The names come directly from the two example words used to teach the rule. Ash-shams (the sun) demonstrates a sun letter, where the lam disappears into the following sound. Al-qamar (the moon) demonstrates a moon letter, where the lam stays clearly audible. Once a student learns these two example words well, they become a useful mental reference point for the whole rule.
Practising Recognition
The fastest way to build this skill is repeated exposure through reading, rather than memorising the two letter lists as an abstract exercise first. Many common words you'll already encounter early in learning, including several place names and everyday vocabulary, demonstrate this rule clearly, so recognition tends to build naturally with regular reading practice and a teacher's correction along the way.
This rule is typically introduced once a student is reading connected words and short phrases confidently, often within a Tajweed course or shortly after finishing Noorani Qaida. If you'd like a teacher to check where you currently stand, a free trial lesson is a straightforward way to find out.