Sun and moon letters
In Arabic and Maltese, all consonants are classified into two distinct groups known as sun letters (Arabic: حروف شمسية ḥurūf shamsiyyah, Maltese: konsonanti xemxin) and moon letters (Arabic: حروف قمرية ḥurūf qamariyyah, Maltese: konsonanti qamrin). 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.