Sun and Moon Letters in Arabic: How Al- Changes Before Each Letter

Sun and moon letters in Arabic decide what happens to the definite article al- (the) when it meets the word that follows it. Before one of the fourteen sun letters the laam (the letter ل) falls silent and the next letter is doubled; before one of the fourteen moon letters the laam is pronounced plainly. Every page of the Quran contains both cases, so settling the rule early makes reading smoother and makes sense of the mushaf's marks.

What the definite article does

Arabic makes a noun definite by attaching al- to the front of it: kitab (a book) becomes al-kitab (the book). The article is written with two letters, alif (ا) and laam (ل), and it is joined to the noun rather than standing apart from it. The alif at the start is a hamzatul wasl (a connecting hamzah), sounded only when the word begins a phrase; our guide to hamzatul wasl and when it is dropped covers that separately.

The sun and moon rule concerns the article's second letter, the laam, and whether it is heard depends entirely on the first letter of the noun. Nothing about the meaning changes; only the sound does.

The fourteen sun letters

The sun letters, called al-huruf ash-shamsiyyah (the solar letters), are these fourteen: ت ث د ذ ر ز س ش ص ض ط ظ ل ن. When the article meets any of them, the laam is not pronounced at all. In its place the sun letter is doubled, and that doubling is marked with a shaddah (the small w-shaped sign that tells you to hold a letter for two beats).

So al + shams (sun) is read ash-shams, not al-shams. The word for the sun begins with ش, a sun letter, and that is exactly where the group takes its name: the sun is the model example of its own rule. In the same way al + rahman is read ar-rahman, and al + nas (people) is read an-nas. Say the doubled letter firmly; the doubling is what carries the article now that the laam is silent.

The fourteen moon letters

The moon letters, al-huruf al-qamariyyah (the lunar letters), are the remaining fourteen: ا ب ج ح خ ع غ ف ق ك م ه و ي. Before any of these the laam is pronounced clearly, with a sukoon (the small circle showing a letter carries no vowel) sitting on it. Al + qamar (moon) is read al-qamar, with the laam fully heard, and the moon lends its name to the group for the same reason the sun did: it starts with ق, a moon letter.

Other everyday examples are al-kitab (the book), al-hamd (the praise) at the opening of Al-Fatihah, and al-jannah (the garden). In each, the noun's first letter is said once and the laam before it is distinct.

If the laam of al- is bare and the next letter carries a shaddah, skip the laam; if the laam carries a sukoon, say it.

How the mushaf shows you which is which

You do not need to memorise both lists before you can read correctly, because the printed mushaf marks every case. Look at the laam.

• Sun letter ahead: the laam carries no sukoon and no vowel at all, and the following letter carries a shaddah. The bare laam is your signal to pass over it.
• Moon letter ahead: the laam carries a sukoon, and the following letter carries only its own ordinary vowel. Pronounce the laam.

If the signs themselves are still new, our article on sukoon and shaddah will make the marks above feel familiar, and the three short vowels covers the rest of the marking system. Once the marks are secure, the sun and moon rule is something you read off the page rather than something you have to remember.

Why the tongue makes this choice

The division is not arbitrary. Laam is formed with the tip and edge of the tongue against the upper gum, just behind the front teeth, and every one of the fourteen sun letters is made with the tip or blade of the tongue in that same neighbourhood. When two sounds are formed in almost the same place, one after the other, the tongue merges the first into the second: the laam is absorbed and the sun letter takes over its beat, which is what the shaddah records.

The moon letters are made elsewhere: in the throat, at the lips, at the back of the tongue. The tongue has to travel to reach them, so the laam keeps its own space and survives. If you enjoy knowing where each sound lives, the seventeen articulation points lays the whole map out, and the sun letters cluster visibly in one region of it.

A practice pair from Surah Ash-Shams

Surah Ash-Shams (91:1–2) opens with an oath by the sun and its brightness, followed in the next ayah by an oath by the moon as it follows the sun. The two nouns arrive one after the other, each carrying the article: wash-shams and then wal-qamar. Read the pair slowly. In the first, the laam vanishes and the ش is held; in the second, the laam is clear before the ق. Few places in the Quran put the whole rule in such a small space, and reciting these two ayat a dozen times fixes the contrast in the ear.

Then extend the habit: on any page you are reading, find every ال and say "sun" or "moon" before reading the word, checking against the marks. After a week you will no longer need to check.

The two errors teachers hear most

The first is pronouncing the laam before a sun letter, giving al-shams or al-rahman. It usually comes from reading letter by letter and trusting the spelling over the marks. The cure is to look at the shaddah before you look at the laam.

The second is dropping the shaddah, so that ash-shams comes out as a-shams, with the ش said only once and the article barely present. The doubled letter needs a moment of held sound; without it the article is barely there. Both errors disappear quickly when a teacher hears them on a live call and models the correction. A Nazra reading course works through exactly this kind of detail page by page, and our Arabic language course teaches the rule alongside the vocabulary it governs. Hafs 'an 'Asim is assumed here; the qira'at (transmitted modes of recitation) share this rule, though they may differ in other details.

Frequently asked questions

Do I have to learn all twenty-eight letters by heart in their groups?

Not at first. The mushaf marks each case, so you can read correctly by watching the sukoon and shaddah. Most students absorb the two lists without trying, simply from meeting the same words repeatedly. Learning the lists deliberately helps later, when you write Arabic or read texts printed without full vowel marks.

Is the laam always written even when it is silent?

Yes. The spelling of the article never changes; it is always alif followed by laam. The silence is a matter of pronunciation only, and the shaddah on the next letter is the written record of it. This is also why dictionaries and indexes list words under the noun rather than under the article.

Why is laam itself counted as a sun letter?

Because when the article meets a word beginning with laam, such as al-layl (the night), the two laams merge and the second is doubled. The result sounds exactly like the pattern of the other thirteen. Since the letter follows the sun behaviour, it belongs in that group.

Does the rule apply outside the Quran?

It applies to all Arabic, spoken and written, in exactly the same way. Someone who has learned it from the Quran will apply it automatically when reading a newspaper or a street sign. The Quran is simply where most learners meet it first and where the marking is most consistent.

Can I hear the difference when listening to recitation?

Clearly, once you know to listen for it. Choose a slow, teaching-style reciter and follow the text with your finger. Every time you see ال, listen for whether the laam is present. Doing this for a page or two trains the ear faster than any list.

Read Ash-Shams to a teacher this week

The quickest way to know whether your sun and moon letters are right is to recite the first two ayat of Surah Ash-Shams to someone who can hear the difference. In our one-to-one classes the teacher listens on a private video call, corrects the laam and the shaddah on the spot, then carries the rule into the pages you are reading anyway. The first class is free and needs no card, and you can ask for a male or female teacher when you book.