Arabic nouns are made definite with "al-" (ال), like "the" in English. In the Qur'an you will see it on almost every page. The laam of "al-" is not always pronounced. Before 14 letters, called the sun letters, the laam disappears into the next letter, which is doubled: we say ash-shams, not "al-shams". Before the other 14, the moon letters, the laam is read clearly with a sukoon: al-qamar. That is the whole rule in two sentences. This guide gives you every letter by name, explains why the tongue behaves this way, shows you how to spot the rule in your own mushaf, and ends with a simple practice routine for adults and children.
What is laam shamsiyyah and laam qamariyyah?
The Arabic alphabet has 28 letters, and they split neatly into two groups of 14. When "al-" comes before one of the 14 sun letters, the laam is called laam shamsiyyah, the "sun laam". It is written but not read. The tongue goes straight to the next letter, and that letter carries a shaddah to show it is doubled. When "al-" comes before one of the 14 moon letters, the laam is called laam qamariyyah, the "moon laam". It is read clearly, with a sukoon, and the next letter is read normally.
In the books of tajweed the two cases have formal names. The sun case is idgham shamsi, "sun merging", because the laam is merged (idgham) into the following letter. The moon case is izhar qamari, "moon clarity", because the laam is made clear (izhar). If you have already met idgham and izhar in the rules of noon sakinah and tanween, these are the same two ideas applied to a different letter.
Why sun and moon? The names come from two words that show the rule perfectly. In ash-shams (the sun) the laam vanishes into the shin. In al-qamar (the moon) the laam is heard before the qaf. Every other "al-" word behaves like one of these two, so scholars named the groups after them. You can hear both in the Qur'an, for example in wash-shamsi wa duhaha (Ash-Shams 91:1) and wanshaqqal-qamar (Al-Qamar 54:1).
One more piece belongs here. The "a" at the very start of "al-" is a hamzatul wasl: you only pronounce it when you begin reading from that word, and you skip it when you join from the word before. We cover it fully in our guide to hamzatul wasl, and it comes up again below when we look at joining words.
Why does the laam merge before the sun letters?
The reason is in the mouth, not in a list to memorise. Look at where the sun letters are made. Most of them are produced with the tip or front of the tongue, touching or coming close to the teeth and the gum ridge: ta (ت), dal, ta (ط), tha, dhal, za (ظ), sin, sad, zay, ra, noon and laam itself. The laam is made with the edge of the front of the tongue in the same area. When two sounds are made in almost the same place, it is heavy for the tongue to say one with a sukoon and then the other straight after. So the laam is absorbed into its neighbour, and the neighbour is doubled.
Two sun letters, shin and dad, are made a little further back: shin from the middle of the tongue, dad from its side. Scholars of tajweed explain that each has a quality that carries it towards the front of the mouth. Shin has tafashshi, a spreading of the air through the mouth, and dad has istitalah, a lengthening of its sound along the side of the tongue until it reaches the area of the laam. That closeness is enough for the merging.
The moon letters, on the other hand, are made far from the laam. Some come from the throat (hamzah, ha (ه), 'ayn, ha (ح), ghayn, kha), some from the back of the tongue (qaf, kaf), some from the middle of the tongue (jim, ya), and some from the lips (ba, meem, waw, fa). Because they are distant from the laam, there is nothing heavy about pronouncing the laam first, so it stays clear. If you would like to see each letter's point of articulation, our guide to makharij al-huroof maps them one by one.
Why this helps you
Once you understand that the sun letters are the tongue-tip letters, you rarely need to look anything up. If your tongue is already near the front of the mouth for the next letter, the laam merges. If the next sound starts in the throat, at the back of the tongue or on the lips, the laam stays.
Which are the 14 sun letters?
The 14 sun letters are: ta (ت), tha, dal, dhal, ra, zay, sin, shin, sad, dad, ta (ط), za (ظ), laam and noon. Each example below is taken from the Qur'an:
Arabic teachers remember the sun letters from the first letter of each word in this line: طب ثم صل رحما تفز ضف ذا نعم دع سوء ظن زر شريفا للكرم. The line comes from Tuhfat al-Atfal, the short tajweed poem by Sulayman al-Jamzuri that generations of students have memorised. Its words also carry good advice: be good, keep ties, and keep away from bad suspicion.
A few points help with particular letters:
- Laam before laam. In words like al-layl (the night), the laam of "al-" merges into another laam, so you hear one long, doubled laam: wal-layli idha yaghsha (Al-Layl 92:1).
- Noon. An-nas (mankind) is read with a doubled noon, which also carries a ghunnah because every doubled noon does: qul a'udhu bi rabbin-nas (An-Nas 114:1).
- The heavy letters. Sad, dad, ta (ط) and za (ظ) are heavy letters. When the laam merges into them, the whole doubled sound is heavy: as-sirat, ad-dallin, at-tariq (At-Tariq 86:1).
- Ra. Ar-Rahman is read with a doubled, heavy ra. Saying "al-Rahman" is one of the most common slips in recitation.
More surah openings to hear the sun letters: wat-tini waz-zaytun (At-Tin 95:1), wad-duha (Ad-Duha 93:1) and wadh-dhariyat (Adh-Dhariyat 51:1).
Which are the 14 moon letters?
The 14 moon letters are: alif-hamzah, ba, jim, ha (ح), kha, 'ayn, ghayn, fa, qaf, kaf, meem, waw, ya and ha (ه). Here too, each example is from the Qur'an:
The moon letters are also gathered in a phrase from the same poem: ابغ حجك وخف عقيمه, read ibghi hajjaka wa khaf 'aqimah. It means roughly "seek your Hajj, and fear a barren end", and each of its letters is a moon letter.
With a moon letter you pronounce the laam with a light, clear sukoon, then move to the next letter without a break and without adding a vowel. Listen for it in wal-fajr (Al-Fajr 89:1), wal-'asr (Al-'Asr 103:1), al-qari'ah (Al-Qari'ah 101:1), al-kawthar (Al-Kawthar 108:1) and bi rabbil-falaq (Al-Falaq 113:1). Notice that the laam stays light even before a heavy letter such as qaf or kha. The laam of "al-" is always thin, apart from one special case, the laam in the name of Allah, which we come to next.
A tip for the throat letters: some learners rush the laam before 'ayn and ha (ح) and almost swallow it. Give the laam its full, clear sound first, then open the throat for the next letter.
How do you spot sun and moon letters in the mushaf?
You do not need to check a list each time. The mushaf shows you the rule with its marks:
- Sun letter. The laam is left bare, with no sukoon sign on it, and the next letter carries a shaddah. A bare laam followed by a shaddah means: skip the laam.
- Moon letter. The laam carries a sukoon sign and the next letter has no shaddah. A marked laam means: say it.
This is how most modern prints show it, and the principle is the same in an Arabic-style mushaf and an Indian-style mushaf, though the shape of the sukoon sign differs between prints. In the Madinah mushaf and many Arabic-style prints it is a small head shaped like the top of the letter kha (some older Arabic prints use a small circle), while Indian-style prints generally use their own form of the jazm sign. Check the key at the back of your own copy if you are unsure. What matters is the pattern: a marked laam is read, a bare laam before a shaddah is not. If you are moving from one style of print to another, spend a few minutes looking at the "al-" words on a familiar page until the signs feel natural.
The name of Allah follows the sun pattern: ٱللَّهِ. Its laam carries a shaddah, because the laam of "al-" merges into the laam of the word. In this one word the laam is also read heavy after a fatha or damma (as in qalallahu, or nasrullahi in An-Nasr 110:1), and when you begin with the word itself (Allahu, starting with a fatha), and light after a kasra (as in bismillahi or lillahi).
Remember that the rule is only about the laam of "al-". When a laam belongs to the word itself, as in ٱلۡكِتَٰبُ, it is not affected and is pronounced clearly, whatever letter follows.
A common mistake
Reading "al-Rahman" or "al-nas". The ra and the noon are sun letters, so the laam must be dropped: ar-Rahman, an-nas. The written laam is a trap for readers who go by spelling instead of by the marks.
What happens to al- when you start, stop or join words?
Starting on an "al-" word
If you begin reading from a word with "al-", for example at the start of a verse or after a pause, you pronounce the hamzatul wasl with a fatha: "a". Then the rule applies as usual. So you begin with al-hamdu (moon) or ar-Rahman (sun). You never begin with a bare "l" or with the doubled letter alone.
Joining from the word before
When you read straight on from the previous word, the hamzatul wasl is dropped and the last vowel of the previous word joins directly to the laam (or, with a sun letter, directly to the doubled letter). That is why bismillah flows into ir-Rahmanir-Rahim, and why wa plus ash-shams becomes wash-shams.
After a long vowel
If the word before ends in a long vowel, that long vowel is written but shortened in pronunciation, because it would otherwise meet the silent laam (or the first half of the doubled letter). Fi al-ard is read fil-ard, with a short "i". In the same way dhaqa ash-shajarah becomes dhaqash-shajarah (Al-A'raf 7:22), with a short "a". Do not stretch the vowel; the letters of madd are still printed, but they are not read here.
After a sukoon or tanween
If the word before ends in a sukoon or tanween, a short vowel is added to make the join, most often a kasra: qumil-layl (Al-Muzzammil 73:2). After min the added vowel is a fatha: minan-nas. Our hamzatul wasl guide explains these joins in detail.
When you stop on an "al-" word, the rule does not change. You stop on the last letter as usual, and the laam is still merged or clear according to the letter after it.
Do other laams follow the sun and moon rule?
No. Sun and moon apply only to the laam of the definite article. Other laams with a sukoon have their own, simpler rules, and it helps to know them so you do not mix them up.
- The laam of a verb. A laam with sukoon inside a verb, such as in qul (say) or ja'alna (we made), is read clearly before almost every letter, including noon: qul na'am (As-Saffat 37:18).
- Before ra or laam. The exception is when the next letter is ra or another laam. Then the laam merges: qul rabbi is read qur-rabbi (Al-Isra 17:24), and qul la is read with one doubled laam. This is an idgham of the laam into the ra because the two are so close in the mouth.
- The laam of small words. The laam of particles such as hal and bal also stays clear, except before ra or laam: bal rafa'ahullah (An-Nisa 4:158) is read bar-rafa'ahullah. One exception in Hafs: in kalla bal rana (Al-Mutaffifin 83:14) there is a short pause (saktah) on the laam, so it is not merged.
So if a laam is part of the word itself, ask only one question: is the next letter ra or laam? If not, say the laam. If the laam is the laam of "al-", ask the sun-or-moon question instead.
How do you practise the sun and moon letters with real ayat?
You will meet both kinds in one surah: ٱلۡحَمۡدُ (moon), ٱلرَّحۡمَٰنِ (sun), ٱلدِّينِ (sun), ٱلۡمُسۡتَقِيمَ (moon) and ٱلضَّآلِّينَ (sun). Surah Al-Fatihah alone has more "al-" words than these, including ad-din, alladhina and al-maghdub, so it is a perfect daily drill. Read it slowly and say "sun" or "moon" to yourself at each one. Our guide to Surah Al-Fatihah walks through every verse.
A seven-day routine
- Days 1 and 2. Say the 14 sun letters aloud, then the 14 moon letters, with an "al-" word for each. Use the two lines from Tuhfat al-Atfal if you like memorising.
- Day 3. Open any page of the Qur'an and circle (mentally or on a practice copy) every "al-". Mark each as sun or moon by its signs.
- Days 4 and 5. Read Al-Fatihah and the last ten surahs, paying attention only to "al-". Record yourself and listen back.
- Days 6 and 7. Add the joins: long vowels before "al-" (fil-ard), and starting with "a" after a pause. Then test yourself on our tajweed quiz.
Common mistakes to avoid
- Reading the sun laam. "Al-shams", "al-salah", "al-Rahman": always drop it.
- Forgetting the doubling. Dropping the laam but saying the next letter once, so as-sirat sounds like "a-sirat". The shaddah must be held.
- Adding a vowel to the moon laam. "Ala-qamar" or "ali-hamd". The moon laam has a sukoon, nothing more.
- Stretching a long vowel before "al-". Fil-ard, not "fee-al-ard".
- Making the laam heavy. Only the laam of the name of Allah can be heavy; the laam of "al-" is always light.
For children
Children learn this best as a game. Make two cards, one with a sun and one with a moon. Call out an "al-" word, ash-shams, al-qamar, an-nas, al-kitab, and let them hold up the right card. The sun "hides" the laam, as the bright sun makes other lights disappear, while the laam shows up clearly next to the moon. Ten minutes a day for a week is usually enough. Our guide on teaching your child Qur'an at home has more ideas for short, happy lessons.
For a printable summary of this and the other core rules, download our free tajweed wall charts. If you would like a teacher to listen to your recitation and correct it live, our Basic Tajweed course covers the sun and moon letters in its first weeks.
Sources
- The Qur'an, Surah Al-Fatihah (1), verses 1-7.
- The Qur'an, Surah Ash-Shams (91), verse 1, and Surah Al-Qamar (54), verse 1.
- The Qur'an, Surah Al-Isra (17), verse 24, and Surah An-Nisa (4), verse 158, on laam merging into ra.
- Sulayman al-Jamzuri, Tuhfat al-Atfal, the section on the laam of al- (the sun and moon letters).
- Ibn al-Jazari, al-Muqaddimah al-Jazariyyah, on the points of articulation and qualities of the letters.