by Definition

  • 1used to show the person or thing that does something
  • 2used to show the method or tool used to do something
  • 3used to show the amount or number that is multiplied or divided into another number

Using by: Examples

Take a moment to familiarize yourself with how "by" can be used in various situations through the following examples!

  • Example

    The book was written by a famous author.

  • Example

    She painted the picture by using watercolors.

  • Example

    Multiply 5 by 10 to get 50.

  • Example

    Divide 100 by 4 to get 25.

by Synonyms and Antonyms

Synonyms for by

Phrases with by

  • by and by

    after a short time; soon


    By and by, the sun began to set and the sky turned orange.

  • used to introduce a new subject or topic into the conversation


    By the way, did you hear about the new restaurant that just opened?

  • to memorize something completely


    She knows all the lyrics to the song by heart.


Summary: by in Brief

The preposition 'by' [baɪ] is used to indicate the agent or instrument of an action, as in 'The book was written by a famous author,' or 'She painted the picture by using watercolors.' It can also be used to indicate multiplication or division, as in 'Multiply 5 by 10 to get 50,' or 'Divide 100 by 4 to get 25.' Other common phrases include 'by and by,' meaning 'soon,' 'by the way,' meaning 'incidentally,' and 'by heart,' meaning 'from memory.'

How do native speakers use this expression?