Sun and moon letters

In Arabic and Maltese, the consonants are divided into two groups, called the sun letters or solar letters (Arabic: حروف شمسية‎ ḥurūf shamsiyyah) and moon letters or lunar letters (حروف قمرية ḥurūf qamariyyah), based on whether they assimilate the letter lām (ﻝ l)[1] of a preceding Arabic definite article al- (الـ), which is an important general rule used in Arabic grammar. Phonetically, sun letters are ones pronounced as coronal consonants, and moon letters are ones pronounced as other consonants.

Sun letters (red) and moon letters (black)

These names come from the fact that the word for 'the sun', al-shams, pronounced ash-shams, assimilates the lām, while the word for 'the moon', al-qamar, does not.

Rule

When followed by a sun letter, the /l/ of the Arabic definite article al- assimilates to the initial consonant of the following noun, resulting in a doubled consonant. For example, for "the Nile", one does not say al-Nīl, but an-Nīl.

When the Arabic definite article (الْـ) 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. The sun and moon letters are as follows:

Sun letters	ﺕ	ﺙ	ﺩ	ﺫ	ﺭ	ﺯ	ﺱ	ﺵ	ﺹ	ﺽ	ﻁ	ﻅ	ﻝ	ﻥ
	t	th	d	dh	r	z	s	sh	ṣ	ḍ	ṭ	ẓ	l	n
	/t/	/θ/	/d/	/ð/	/r/	/z/	/s/	/ʃ/	/sˤ/	/dˤ/	/tˤ/	/ðˤ/	/l/	/n/
Moon letters	ء	ﺏ	ﺝ	ﺡ	ﺥ	ﻉ	ﻍ	ﻑ	ﻕ	ﻙ	ﻡ	ه	ﻭ	ﻱ
	ʼ	b	j	ḥ	kh	ʻ	gh	f	q	k	m	h	w	y
	/ʔ/	/b/	/d͡ʒ/	/ħ/	/x/	/ʕ/	/ɣ/	/f/	/q/	/k/	/m/	/ɦ/	/w/	/j/

Jīm

The letter ج jīm is pronounced differently depending on the region of the speaker. In many regions it represents a coronal consonant such as [d͡ʒ] or [ʒ]. However, in Classical Arabic, it represented a palatalized voiced velar plosive /ɡʲ/ or a voiced palatal plosive /ɟ/ (and a contemporary pronunciation as [ɡ] or [ɟ] is retained in Egypt, Sudan and southern Yemen / Oman). As a result, it was classified as a moon letter and it never assimilates the article. Maltese ġ /d͡ʒ/ is also considered a moon consonant while its voiceless counterpart ċ /t͡ʃ/ is a sun consonant.

Maltese

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

Sun letters	ċ	d	n	r	s	t	x	ż	z
	/t͡ʃ/	/d/	/n/	/r/	/s/	/t/	/ʃ/, /ʒ/	/z/	/t͡s/, /d͡z/
Moon letters	b	f	ġ	g	għ	h	ħ	j	k	l	m	p	q	v	w
	/b/	/f/	/d͡ʒ/	/g/	/ˤː/	silent	/h/,/ħ/	/j/	/k/	/l/	/m/	/p/	/ʔ/	/v/	/w/

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 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 <i> of the article always drops, as in "dak 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.[2]

Orthography

In the written language, the ال al- is retained regardless of how it is pronounced.[1] When full diacritics are used, assimilation may be expressed by putting a shaddah on the consonant after the lām. Non-assimilation may be expressed by placing a sukūn over the lām.

Most modern-written Arabic names (including personal names and geographical Arabic names) do not follow the consonant assimilation rule or the shaddah when latinized in Latin-spelled languages. Sometimes the sun and moon rules are not followed in casual speech.

E.g. personal name: الرَّحْمَن - Al-Rahman instead of "Ar-Raḥmān";

geographical name: الْجُمْهُورِيَّةُ التُّونِسِيَّة - Al-Jumhuriyah Al-Tunisiyah instead of "al-Jumhūrīyatu ’t-Tūnisīyah".

Examples

Sun letters			Moon letters
الشَّمْس	ash-shams	'the sun'	الْقَمَر	al-qamar	'the moon'
الثِّقَة	ath-thiqah	'the confidence'	الْمُرْجَان	al-murjān	'the coral'

Sun/Solar Letters حروف شمسية ḥurūf shamsīyah					Moon/Lunar Letters حروف قمرية ḥurūf qamarīyah
Letter	IPA	"lām" assimilated to definite article "al" along with shaddah (الْـّ)	Examples		Letter	IPA	"lām" NOT Assimilated to definite article "al" (الْـ)	Examples
ت t	/t/	− التّـ ’at-t...	التِّينُ at-tīn(u) = the fig		ء ʼ	/ʔ/	− الْإـ, الْأـ al-’a.../ al-’u...; al-’i...	الْأَخُ al-ʼakh(u) = the brother الْأُذُنُ al-’udhun(u) = the ear الْإِبْرِيقُ al-’ibrīq(u) = the jug
ث th	/θ/	− الثّـ ath-th...	الثَّعْلَبُ ath-tha‘lab(u) = the fox		ب b	/b/	− الْبـ al-b...	الْبَيتُ al-bayt(u) = the house
د d	/d/	−الدّ ’ad-d...	الدُّبُّ ad-dubb(u) = the bear		ج j	/d͡ʒ/	− الْجـ al-j...	الْجَوزُ al-jawz(u) = the walnut
ذ dh	/ð/	−الذّ adh-dh...	الذَّكَرُ adh-dhakar(u) = the man, male		ح ḥ	/ħ/	− الْحـ al-ḥ...	الْحَجُّ al-Ḥajj(u) =the Hajj pilgrimage
ر r	/r/	−الرّ ar-r...	الرَّبُّ ar-Rabb(u) = the Lord (Allah)		خ kh	/x/	− الْخـ al-kh...	الْخَوْخُ al-khawkh(u) =the peach
ز z	/z/	−الزّ az-z...	الزَّنْبَقُ az-zanbaq(u) = the lily		ع ʻ	/ʕ/	− الْعـ al-‘a.../ al-‘u.../ al-‘i...	الْعَقْلُ al-‘aql(u) = the mind الْعُشْبُ al-‘ush·b(u) = the grass الْعِيدُ al-‘id(u) = the holiday/ festival
س s	/s/	− السّـ as-s...	السَّمَاوَاتُ as-samāwāt(u) = the Heavens/ firmament, skies		غ gh	/ɣ/	− الْغـ al-gh...	الْغَرَامُ al-gharām(u) = the love, warmth, romantic
ش sh	/ʃ/	− الشّـ ash-sh...	الشَّرْقُ ash-shar·q(u) = the east		ف f	/f/	− الْفـ al-f...	الْفِكْرُ al-fik·r(u) = the thought
ص ṣ	/sˤ/	− الصّـ aṣ-ṣ...	الصَّحْرَاءُ aṣ-ṣaḥ·rāʼ(u) = the desert		ق q	/q/	− الْقـ al-q...	الْقِرْدُ al-qir·d(u) = the monkey
ض ḍ	/dˤ/	− الضّـ aḍ-ḍ...	الضَّبَابُ aḍ-ḍabāb(u) = the fog		ك k	/k/	− الْكـ al-k...	الْكَوْكَبُ al-kawkab(u) = the planet
ط ṭ	/tˤ/	− الطّـ aṭ-ṭ...	الطَّاهِرُ aṭ-ṭāhir(u) = the pure		م m	/m/	− الْمـ al-m...	الْمَتْحَفُ al-mat·ḥaf(u) = the museum
ظ ẓ	/ðˤ/	− الظّـ aẓ-ẓ...	الظُّهْرُ aẓ-ẓuh·r(u) = the noon		و w	/w/	−الْو al-w...	الْوَفِيَُ al-wafiyy(u) = the faithful
ل l	/l/	− اللّـ al-l...	اللَّوْنُ al-lawn(u) = the colour		ي y	/j/	− الْيـ al-y...	الْيَانْسُونُ al-yānsūn(u) = the anise
ن n	/n/	− النّـ an-n...	النِّسَاءُ an-nisāʼ(u) = the women		ه h	/h/	− الْهـ al-h...	الْهَوَاءُ al-hawāʼ(u) = the air, kiss of life

See also

• Arabic phonology
• Arabic grammar

References

1. Abboud, Peter F.; et al. (1983). Elementary Modern Standard Arabic 1. Cambridge UP. pp. 123–124. ISBN 0-521-27295-5.
2. Aidan. "The Definite Article in Maltese".