"eius". The pronunciation of it has always historically been EE. But that does not quite exhaust the possibilities of error. In elementary school in South Wales before the war (Americanice 'fourth grade'), in sporadic and unenthusiastic Welsh lessons we were taught to say it as the English EYE. And this hyper-pedantic noise was occasionally heard even out of school from people who were trying to impress. Without trying to pun: this is an example of an 'eye-pronunciation' --the wrong pronunciation of a word to fit with its apparent spelling. In English we have well-established pedantic misspellings like "posthumous" and "Anthony" for the etymological "postumous" and "Antony". The second of these is often given an incorrect eye-pronunciation in American usage, where you can hear ANTH-ony, and even have people claim that this is their name