Combining Double Acute Accent

Attach it to a base letter.

In Hungarian, adding the double acute after o or u gives ő or ű, corresponding to the long-vowel letters ő and ű (contrasting with short ö and ü). When a keyboard or character picker offers them, enter the ready-made letters.

Chuvash is written in Cyrillic; its letters Ӳ and ӳ correspond to Cyrillic У and у plus this mark. The base letter and spelling system determine the result.

Where did the double acute come from?

It developed through Hungarian manuscript and print practice.

The earliest preserved Hungarian text, the Halotti Beszéd (a funeral sermon), dates to the turn of the 12th and 13th centuries and lacks original diacritics. Manuscript marks that look similar may instead be ligatures, where letters are joined in writing, or uncertain additions.

Recognizable long-vowel notation appears in 18th-century Hungarian material first as a diaeresis-plus-acute form. The modern hungarumlaut replaces that transitional form at the turn of the 18th and 19th centuries; the 1832 Academic Orthography marks the point when the diacritic system appears unified.

Why does the combining double acute look wrong?

Fonts place its strokes differently.

Because ̋ combines with the base, font metrics affect its angle, height, and horizontal offset. Text and display typefaces can draw it differently, so a mark viewed alone may not resemble one shown with a letter.

In early Windows and Word-era fonts, some improvised fonts imitated Hungarian double-accent letters by placing two acute accents. The spacing character ˝ stands on its own; ̋ attaches to a base.