by
by: at the side of or close to something. From this core idea, by also extends to deadlines, methods, standards, and changes in amount.
- Core image: one thing is at the side of another or leaning on it.
- Time: by + time means no later than that point.
- Abstract uses: by can show method, basis, or amount of change.
Scene category
Controls
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Examples
Spatial examples
Stand by the door.
There is a small cafe by the station.
A lamp stood by the bed all night.
Time examples
Please send the form by noon.
Be home by ten tonight.
By Friday, we need a final answer.
Abstract examples
We traveled by bus.
Judge the plan by its results, not by its promises.
Prices went up by 10 percent this year.
Related prepositions
Key differences
Start with the spatial picture: by puts something at the side of another thing. From there it extends to time limits, method, basis, and amount, so compare it with near, next to, and until instead of memorizing one loose translation.
Near is a broad idea of closeness. By usually sounds more anchored to the side of something and often feels a little closer.
Next to is stricter side-by-side contact or direct adjacency. By is looser and more natural when you only need the idea of being at the side of something.
By + time means no later than that time. Until + time means something continues up to that time.
Quick check questions (decision tree)
Is it a specific day/date (a particular day) or weekday?
Yes -> often by (compare: months/years/periods often use next to; exact clock times often use near).
Is it an exact clock time (hour/minute)?
Yes -> more likely near; if it's a date/weekday, use by.
Is it a longer time period (month/year/season/part of day)?
Yes -> more likely next to; by is often for a specific day/date.
Is the meaning a deadline ('no later than') or a bounded range?
Yes -> switch to a deadline/range preposition; No -> stay with day/time/period checks.
Common collocations
Place and position
Deadlines and time points
Method, basis, and amount
Common mistakes
Avoid: We went with bus.
Use: We went by bus.
Reason: Use by to show the method of transport in common travel expressions.
Avoid: Please finish it until Friday.
Use: Please finish it by Friday.
Reason: By Friday means no later than Friday. Until Friday means something continues up to Friday.
Avoid: The lamp is next the bed.
Use: The lamp is by the bed. / The lamp is next to the bed.
Reason: English needs by or next to here. Next the bed is not a natural phrase.
Mini quiz
Question 1
Choose the correct preposition: There is a chair ___ the window.
Choose an answer
Question 2
Choose the correct preposition: Please send it ___ noon.
Choose an answer
Question 3
Choose the correct preposition: We traveled ___ train.
Choose an answer
Quick FAQ
What is the core meaning of "by"?+
The core idea of by is "at the side of" or "close to." Picture one thing next to another thing, often almost touching it.
How is "by" different from "near"?+
Near is a broad idea of closeness. By often feels more anchored to the side of something and can sound slightly closer or more exact.
How is "by" different from "beside" or "next to"?+
Beside and next to are stronger for direct side-by-side adjacency. By is more flexible and natural when you only need the idea of being at the side of something.
Can "by" be used for time?+
Yes. By + time means no later than that point: by noon, by Friday, by the end of class.
What does "by bus" mean?+
By bus shows method or means. It means "using the bus as the way to travel," just like by train or by email.
What does "judge by" mean?+
Judge by means "use something as the basis or standard." For example, judge the plan by its results.
What does "by 10 percent" mean?+
By 10 percent shows the amount of change. Prices rose by 10 percent means the increase was 10 percent.
How can I remember "by" quickly?+
Start with one image: something is by your side. Then extend it: close to a place, close to a time point, or relying on a method or standard.