"The Bulgarian Minister for Magic attends the Quidditch World Cup match between Bulgaria and Ireland. Cornelius Fudge cannot pronounce his name, but thinks it might be Mr Oblansk, or Mr Obalonsk."
From the Story
Discovered in Book 4, Chapter 8, The Quidditch World Cup
The Bulgarian Minister for Magic wears splendid robes of black velvet trimmed with gold to the match. He doesn't appear to understand a word of English, and doesn't respond when Cornelius Fudge introduces him to Harry Potter. He spots Harry's scar moments later and starts gabbling loudly and excitedly, pointing at it.
At the end of the Quidditch match, the Bulgarian Minister muses dejectedly that the Bulgarian team had fought bravely, revealing that he does in fact speak English. He tells Fudge that he found his miming very funny, which is why he didn't reveal this before.