This is new. My dropdown plurk verbs menu is suddenly in another language I lack the expertise to identify.
Go to your name, where the language menu is. Choose anything else, then change it BACK to English.
That being said - is it kanji or Roman-type letters?
Kanji. If it were Roman-type letters I'd have probably tried googling. <grin>
They provide a BUNCH of Chinese languages for Plurk.
Good for them! I just wasn't expecting them to suddenly be provided to me. 
Also, thank you. That appears to have fixed it.
Old bug.