Foundations

Sun & moon lettersالحُرُوف الشَّمْسِيَّة وَالقَمَرِيَّة

Arabic has one definite article: الـ (al-), meaning “the”. How it’s pronounced depends entirely on the first letter of the noun it attaches to. The 28 letters split cleanly in half — 14 “sun” letters that swallow the lām, and 14 “moon” letters that keep it intact.

Sun-letter ruleالحُرُوف الشَّمْسِيَّة

The lām of ’al-’ is silent. The first letter of the noun is doubled (shaddah). ’al-shams’ is read ’ash-shams’.

شَمْس→الشَّمْس

ash-shams — the sun

Moon-letter ruleالحُرُوف القَمَرِيَّة

The lām of ’al-’ is clearly pronounced (sukūn on the lām). The noun’s first letter starts normally. ’al-qamar’ stays ’al-qamar’.

قَمَر→الْقَمَر

al-qamar — the moon

The 14 sun letters

ash-shamsiyyah — assimilate the lām

tā'

thā'

dāl

dhāl

rā'

zāy

sīn

shīn

ṣād

ḍād

ṭā'

ẓā'

lām

nūn

The 14 moon letters

al-qamariyyah — keep the lām

alif

bā'

jīm

ḥā'

khā'

ʿayn

ghayn

fā'

qāf

kāf

mīm

hā'

wāw

yā'

Try it yourself

Tap a noun to see ’al-’ in action

12 examples

Bare noun

شَمْس

shams

Plus ’al-’ prefix

الشَّمْس

ash-shams

First letter

Sun letter

Sun-letter rule: the ل of الـ is silent. The first letter of the noun is doubled (a shadda sits on it). Pronounce “ash-shams”, not “al-shams”.

Why the names?

The two classic words used to illustrate the rule are الشَّمْس (“the sun”, ash-shams) and القَمَر (“the moon”, al-qamar). The sun-letter group is named after the first and the moon-letter group after the second. It’s just terminology — there’s no deeper astronomy involved.