- Sevilla is Spanish. It is pronounced 'Se-bi-ya', never 'Se-vil-a'.
- Seville is English. It is pronounced 'Se-vil'. When speaking in English, this pronunciation is the only acceptable pronounciation.
The football team, however, is usually Sevilla and not Seville, however foreign football team names in English is a black art and even the revered BBC confuse themselves, using the English 'Bayern Munich' (rather than the German 'Bayern München') but using the Spanish 'Sevilla' instead of the English 'Seville'. Decide for yourself what's right!