Vietnamese

How Vietnamese came to have six tones

Tones grew out of consonants. Syllables that once ended in a glottal stop or in s or h developed distinct pitches, and a later split separated syllables with voiced initials from those with voiceless ones. The voiced set was pronounced with breathy or creaky voice and lower pitch; when the voiced stops lost their voicing, those differences became tones in their own right. In the north, around Hanoi, voice quality still carries most of the difference, while in the south, around Ho Chi Minh City, pitch does. Every syllable now bears one of six tones. Borrowings from Middle Chinese, the Sino-Vietnamese vocabulary, brought in the retroflex sounds now spelled s and tr.

Why chữ Nôm gave way to the Latin alphabet

After a millennium of Chinese rule ended in 939, the Vietnamese state wrote in Literary Chinese. From around the 13th century scholars built chữ Nôm, Southern characters, out of Chinese characters and thousands of new compounds to write Vietnamese itself. It peaked in the 18th century with Nguyễn Du and Hồ Xuân Hương, yet was official only under the Hồ and Tây Sơn dynasties.

The missionaries' alphabet stayed mostly within Catholic writing for more than 200 years. In 1910 a decree of the French Résident Supérieur of Tonkin required it for all public documents, and reformists and nationalists spread it further; it became the official script on independence. North Vietnam's education reform of 1950 ended the teaching of Chinese characters and chữ Nôm. The alphabet has 29 letters, adding đ, ă, â, ê, ô, ơ and ư, and leaves out f, j, w and z. Tone marks can stack on vowel marks, as in ể.

Where the dialects part ways

Vietnamese is traditionally divided into Northern, Central and Southern varieties, and Modern Standard Vietnamese is based on the Hanoi dialect. The North pronounces both d and r as [z], while the Central and Southern dialects keep sounds closer to the spelling. The South shows less internal variation because Vietnamese speakers settled it late, around the end of the 15th century. After the partition of 1954 about a million Northerners moved south, and many Southern residents now speak with a somewhat Northern accent.