Seeking for formal foreign words in English
Salutations everyone on iTalki!
I am looking for any foreign words and/or loanwords that sounds more formal and sophisticated rather than informal, vulgar, and laid-back. I know that saying 'n'est-ce pas?' is more formal than saying 'isn't it?' and 'ultra vires' is a formal Latin phrase and it can only be used for law. Some French words such as 'au contraire' (on the contrary) can be humorous which is informal. I am using a book called "Faux Pas? A No-Nonsense Guide to Words and Phrases from Other Languages" by Philip Gooden. The purpose is to become more sophisticated and 'upper-class' at the English language skills even though I am fluent for over a score (20 years) since the age of 6 in the USA. I moved from the Philippines in 1999 which English is my only mother tongue. I apologize for any annoyance. Thank you so much for your time to read my topic.