Use as…as to say two things are equal: She is as tall as her brother. Use not as…as to show inequality: This film isn't as good as the book. Multipliers like twice as…as show how much bigger or smaller.

Use as…as to say two things are equal: She is as tall as her brother. Use not as…as to show inequality: This film isn't as good as the book. Multipliers like twice as…as show how much bigger or smaller.