LOL, I've done that so many times, written half an answer in English, then half in Esperanto and it takes me a moment or two before I realise why the stupid computer is telling me I'm wrong when it was such an easy one.

Same remark. What I hear is "Ŝi volas fendi (or vendi) leteron".

I didn't get it in this one, but I have had a similar problem before and I put it down to me not being familiar with the sound and rhythm of the language?