Depending on location, English can vary a lot! The following 5 words suffer from British vs. American confusion all the time.

The words themselves are easy, but British and American English treat them differently.

(1) Analyze or analyse? Analyze is the American spelling. You’ll never see analyze in British English. Verbs in British English end in –yse, not –yze. Therefore, in British English, you’ll write, “He analyses the data”, “She analysed the data”, and “They are analysing the data”. The plural noun of “analysis”, though, is “analyses” in both British and American English.

(2) Defence or defense? Defense is the American spelling. Defence is the British spelling. However, many institutions’ have this word in their name, and we should always respect a name’s spelling: Therefore the Japanese Self-Defense Forces, for example, would be spelled that way (Defense with an ‘s’) even in a British English paper.

(3) Per cent  or percent? Percent is the American spelling. Per cent is the British spelling. That said, ‘percentage’ is always spelled the same. If you’re struggling, RPB suggests just using the ‘%’ symbol.

(4) Program and programme. American English uses only program. British English uses program AND programme: In British English, a program is a series of instructions for a computer (like software). A programme is a series of planned activities/events, a television show, or a small booklet shared before an event.

(2) Organisation or organization? Organization is the American spelling, always and every time. British English, however, is debating the issue: As long as you’re consistent, either option is acceptable. So if you choose organisation, you need to use, for example, generalisation, globalisation, and realisation too.