Pronunciation of English ⟨wh⟩

It is now most commonly pronounced /w/, the same as a plain initial ⟨w⟩, although some dialects, particularly those of Scotland, Ireland, and the Southern United States, retain the traditional pronunciation /hw/, generally realized as [ʍ], a voiceless "w" sound.

Before rounded vowels, a different reduction process took place in Middle English, as a result of which the ⟨wh⟩ in words like who and whom is now pronounced /h/.

What is now English ⟨wh⟩ originated as the Proto-Indo-European consonant *kʷ (whose reflexes came to be written ⟨qu⟩ in Latin and the Romance languages).

In reference to this English order, a common cross-lingual grammatical phenomenon affecting interrogative words is called wh-movement.

A similar process of labialization of /h/ before rounded vowels occurred in the Middle English period, around the 15th century, in some dialects.

[4] It was unacceptable in educated speech until the late 18th century, but there is no longer generally any stigma attached to either pronunciation.

[3] In the late nineteenth century, Alexander John Ellis found that /hw/ was retained in all wh- words throughout Cumbria, Northumberland, Scotland and the Isle of Man, but the distinction was largely absent throughout the rest of England.

[5] The merger is essentially complete in England, Wales, the West Indies, South Africa, Australia, and in the speech of young speakers in New Zealand.

In some accents, however, the pronunciation is more like [hʍ], and in some Scottish dialects it may be closer to [xʍ] or [kʍ]—the [ʍ] sound preceded by a voiceless velar fricative or stop.