How to Use “By” in English
“By” is a small word with many jobs. It can describe who performed an action, how something was done, when a task must be finished, or where something is located. Understanding the context makes its meaning easier to recognize.
To Name the Doer of an Action
In a passive sentence, “by” can introduce the person or thing responsible for an action.
- The novel was written by Toni Morrison.
- The window was broken by the wind.
The phrase beginning with “by” can often be left out when the doer is unknown or unimportant: The window was broken.
To Describe a Method or Means
“By” can explain how someone does something or what means they use.
- She sent the document by email.
- He learned to cook by practicing every weekend.
- We traveled by train.
When “by” is followed by a verb to describe a method, that verb usually takes the -ing form: by reading, by asking, or by working together.
To Set a Deadline
“By” can mean “no later than” a particular time. The action may happen before that time, but it must happen by then.
- Please submit the form by Friday.
- The package should arrive by noon.
This meaning differs from “until.” I’ll finish by Friday means the work will be complete no later than Friday. I’ll work until Friday means the work will continue up to Friday.
To Describe Location
When “by” refers to a place, it often means “beside,” “near,” or “past.”
- There’s a small café by the station.
- She sat by the window.
- We drove by the old school.
In the last example, “drove by” means the car passed the school.
To Identify an Author or Creator
“By” appears in titles and credits to name the person who created a work.
- A poem by Langston Hughes
- Music by the local orchestra
In Measurements and Calculations
“By” can express multiplication or dimensions.
- Multiply six by four.
- The room is ten feet by twelve feet.
Common Expressions with “By”
The word also appears in many everyday phrases:
- by hand — made or done without a machine
- by chance — accidentally or unexpectedly
- by mistake — unintentionally
- by yourself — alone or without help
- by the way — used to add a related or secondary point
A Word Worth Noticing
“By” can signal an agent, method, deadline, location, creator, or measurement. Rather than relying on a single definition, look at the words around it. The sentence usually reveals which meaning fits.
5 Ways to Use ‘By’: From Deadlines to Descriptions
- Use “by” to show who did something
- Use “by” for a deadline
- Use “by” to describe how you travel
- Use “by” to mean “next to”
- Use “by” to show a method
Use “by” to show who did something
Use “by” to show who performed an action, especially in a passive sentence. For example, “The song was written by Maya” tells you who wrote it, while “The package was delivered by the courier” identifies who delivered it. The phrase with “by” can be left out when the person responsible is unknown or not important: “The package was delivered.”
Use “by” for a deadline
Use “by” to set a deadline, meaning something must happen no later than a specific time. For example, “Please send me the report by Friday” means it can be sent earlier, but it must arrive on or before Friday. This differs from “until,” which describes how long an action continues: “I’ll work until Friday” means the work will continue through that point.
Use “by” to describe how you travel
Use “by” to describe the way you travel. For example, say “I go to work by bus,” “We traveled by train,” or “She came by car.” When “by” is followed by a type of transportation, don’t use “a” or “the”: say “by plane,” not “by a plane.” However, use “on foot” when you walk.
Use “by” to mean “next to”
Use “by” to mean “next to” when describing something located beside or near another thing. For example, “She left her keys by the door” means the keys are next to the door. This use is common when talking about where people or objects are: “He sat by the window,” or “There’s a café by the station.”
Use “by” to show a method
Use “by” to explain the method or means used to do something. When a verb follows “by,” use its -ing form: “She improved her writing by reading every day” or “They solved the problem by working together.” You can also use “by” with a noun to describe a method, as in “We traveled by train” or “He paid by credit card.”
