What are similes and metaphors? Similes compare two things. Some similes use the word as. Some similes use the word like. Metaphors are like similes. They compare two different things, but they do not use like or as. In this book, you will learn how to use similes and metaphors. This book is part of the Language Rules series. Each book in this series provides hints, examples, and funny illustrations to help readers master a different part of speech.