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: student
In the UK, a student is someone who is studying at university or college. A child at school is usually called a pupil. In the US, student can refer to anyone who is studying at school or university. British speakers use postgraduate to refer to someone who has finished their bachelor's degree(=first degree) and is studying for an advanced degree. In the US, you would call this person a graduate student.