90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.
Differences between British and American English: theatre
In both the UK and the US, a theatre is a place where people watch plays or other performances. In the US, you can also use theater or movie theater to mean a place that shows films. In the UK, you see a film at a cinema.