We can use the English preposition "by" in a few different ways. In this lesson, we will cover all of the different ways that we use the preposition "by".

1. We use "by" in many expressions to say how we do something. Here are some common expressions.

by email	by phone	by hand	by check
by credit card	by bus	by car	by subway
by mistake	by accident	by chance	by sea
by air	by bike	by train	by message

Note: The opposite of "by mistake/accident" is "on purpose". We use "in cash" not "by cash". We use "on foot" not "by foot".

• We traveled by bus.
• I went there by subway.
• The army attacked by air and sea.
• She wrote the letter by hand.
• I sent it by email, but she wanted me to send it by fax.
• I contacted her by phone.
• Did you come by plane?
• Did he do that by mistake?
• I hit her by accident.

2. We also use "by" in the passive voice.

• She was hit by a baseball.
• The TV show was watched by millions of people.
• This picture was painted by Salvador Dali.
• Who was this book written by?
• This is a story by Shakespeare.
• This watch was made by a famous watchmaker in Switzerland.

3. "By" can also have the same meaning as "next to / beside" or "near".

• She sat by me.
  (=She sat next to me.)


• The light is by the door.
  (=The light is next to the door.)


• I live by her.
  (=I live near her.)


• It is by my house.
  (=It is near my house.)

Note: We do not know exactly if it is "next to" or "near" from these sentences, but we can usually guess or it is not really important to know exactly. If you do not know and you want to know, then just ask the other person.

4. We use "by" to show how much something increased or decreased.

• Gas prices increased by $1. Last week, gas prices were $3 and this week they are $4.
• My salary will increase by 25% next year.
• Our sales decreased by 10% last quarter.

Prepositions are one of the hardest things for people who are learning English to master. But you should not worry about prepositions too much. Most times, if you make a mistake with a preposition, the other person can still understand what you are saying. However, if you want to be an excellent or fluent English speaker, then you must know how to use prepositions correctly. It will take time to master English prepositions, but if you study these lessons and come back to review them often, then you will gain a better understanding of how and when to use each English preposition.