Sun and moon letters

Distinction between two groups of Arabic consonants

In Arabic and Maltese, the consonants are divided into two groups, called the sun letters or solar letters and moon letters or lunar letters, based on whether they assimilate the letter lām 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.

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