different : 普通用词，强调事物间的区别或本质的不同。有时侧重对比，不着重差别。
- She seems to wear something different every day.
- He's different now that he's been to college.
- We're reading a different book this week.
- Emily is very/completely/entirely different from her sister.
- Emily and her sister are completely different.
- There are many different types/kinds of bacteria.
various : 通常强调种类的数目。
- We had various problems on our journey, including a flat tyre.
- The author gave various reasons for having written the book.
- Girardo was out of action with various injuries for most of last season.
- Various people whom we weren't expecting turned up at the meeting.
diverse : 语气较强，指性质完全不同，着重显著的区别。
- people from diverse cultures
- My interests are very diverse.
- Jones has a much more diverse and perhaps younger audience.