Which preposition to use with pronounciation

of Occurrences 1%

Horatio understood the language perfectly well, having conversed so long with Swedes, but never could attain to a perfect pronounciation of it, so replied in French, that he knew the prince could speak French, and he would therefore answer to any interrogatories his highness should be pleased to make without the help of an interpreter.

Which preposition to use with  pronounciation