Arabic Letter Khah

It marks a rough kh sound made at the back of the mouth.

The kh is one consonant, not k followed by h. Scottish loch and German Bach have a similar rasp. Persian also uses this letter, commonly written x or kh in Latin transliteration, as does Urdu.

How did خ develop?

Arabic writing developed gradually from Nabataean, an older script adapted to write Arabic. The En Avdat hymn preserves Arabic in Nabataean writing, likely before 150 CE; the Namara funerary inscription of 328 CE marks another stage in the script's development. These are milestones in Arabic writing, not dates for the modern dotted letter.

Why does خ change shape?

Its outline changes when it joins neighboring letters. The same character has connected forms at the beginning, middle, or end of a word, and a separate form when it stands alone.

The dot is part of the letter's identity. Early Arabic manuscripts could leave ج, ح, and خ ambiguous because their basic outlines were shared; distinguishing dots mark different consonants.

A Nabataean ḥet sign could represent sounds later written with both ح and خ in Arabic. That history connects the letters without making them interchangeable.