Sun and moon letters

In Arabic and Maltese, all consonants are classified into two distinct groups known as sun letters ( ', ) and moon letters (Arabic: ', ).

This distinction affects the way the definite article (equivalent to "the" in English) is assimilated or pronounced before consonants: when a word begins with a sun letter, the definite article assimilates with the initial consonant of the word.

The names stem from how the definite article interacts with the nouns "Sun" and "Moon" in Arabic (and Maltese). In Arabic, al-shams (“the Sun”) becomes ash-shams (assimilating the lām), while al-qamar (“the Moon”) remains unchanged. Similarly, in Maltese, "the Sun" is ix-xemx (with assimilation), while "the Moon" is il-qamar (without assimilation).

Rule

When followed by a sun letter, the of the Arabic definite article assimilates to the initial consonant of the following noun, resulting in a doubled consonant. For example, "the Nile" is pronounced , not .

When the Arabic definite article (<span style="font-size:135%;"></span>) is followed by a moon letter, no assimilation takes place.

The sun letters represent the coronal consonants according to the phonology of Classical Arabic, and the moon letters represent all others. Note that the mnemonic (pronounced somewhat like aibgh hajak wakhaf eaqimah) groups all moon letters.

The sun and moon letters are as follows:

JÄ«m

The letter <span style="font-size:135%;"></span> is pronounced differently depending on the region of the speaker. In many regions it represents a coronal consonant such as or . However, in Classical Arabic, it represented a palatalized voiced velar plosive or a voiced palatal plosive . A contemporary pronunciation as is retained in Egypt, Oman, and coastal Yemen or in eastern hinterland Yemen, and as a variant in Sudan. As a result, it was classified as a moon letter, and it does not assimilate the article in Classical Arabic. Maltese ġ is also considered a moon consonant, whereas its voiceless counterpart ċ is a sun consonant.

However, in some varieties of Moroccan, Mesopotamian, and Palestinian Arabic, (often //) assimilates, like a sun letter, e.g., 'camel'.

Emphatic consonants

In Arabic dialects, like Palestinian, al before an emphatic consonant only assimilates in place of articulation but not in pharyngealization, hence instead of ( 'table').

Maltese

The sun (konsonanti xemxin) and moon (konsonanti qamrin) letters are as follows:

If a word starts with any of the moon letters, the definite article il- stays the same and does not assimilate, while with the sun letters it assimilates accordingly to: iċ-, id-, in-, ir-, is-, it-, ix-, iż-, iz-. It is also worth mentioning that words starting with vowels, and the letters għ, and h get the definite article l- (minus the initial i). When the definite article comes exactly after a word ending in a vowel, the initial <nowiki><i> of the article always drops, as in "dak </nowiki>ir-raġel ra r-raġel" (that man saw the man). When a word starts with two consonants, the definite article used is l-, but an i is attached at the beginning of the word: skola > l-iskola and Żvezja > l-Iżvezja.

The sound (represented by the letters and ) function in the same way no matter it is sun or moon letter, e.g. (the meat) is il-laħam in Maltese and al-laḥm in Arabic or (the game) is il-logħba in Maltese and al-luʿ<nowiki/>ba in Arabic.

Orthography

In the written language, the ⟨<span style="font-size:150%; line-height:1;"></span>⟩ is retained regardless of how it is pronounced. When full diacritics are used, assimilation may be expressed by putting a ' ⟨ ّ⟩ on the consonant after the ⟨<span style="font-size:150%; line-height:1;"></span>⟩. Non-assimilation may be expressed by placing a over the ⟨<span style="font-size:150%; line-height:1;"></span>⟩.