Noun + Preposition (by)

Fixed Expressions with by (No Article)

Some common expressions use by + noun with no article (no the, no a). These describe how something happens.

Expression	Meaning
by mistake	you did not plan it
by accident	it was not intentional
by chance	it was not arranged

• I sent the email to the wrong person by mistake.
• We discovered the billing error by accident.
• I ran into my old manager at the airport by chance.

Be careful: to say someone did something intentionally, use on purpose (not by purpose).

• He didn’t submit the report late on purpose. It was an accident.

How People Travel: by + Transport

Use by to describe a method of transport. No article is needed.

by car	by train	by plane
by bus	by bike	by boat / by ship

• Most of our staff get to the office by train.
• The parts were shipped by boat to save on costs.

When You Add an Article or Possessive

If you add my, the, a, or any other determiner, you cannot use by. Switch to in or on.

by + noun (general)	in / on + specific vehicle
by car	*in my car*
by train	*on the 8:15 train*
by taxi	*in a taxi*

Use in for cars and taxis:

• They arrived in a company car, not in a taxi.

Use on for bikes and public transport (buses, trains, etc.):

• Half the team was already on the bus when it left.
• She reads reports on the train every morning.

Note: the usual expression is on foot (not by foot).

• The office is close, so I walk there on foot.

Other Methods: by post, by card, by hand

You can also use by for other methods of doing things.

• Could you send the signed contract by post?
• Can I pay by credit card?
• These labels need to be applied by hand — the machine can’t do it.

Exception: we say pay cash or pay in cash (not by cash).

• Some vendors only accept payment in cash.

Passive: Done by Someone / Something

In passive sentences, use by to say who or what performs the action.

• The quarterly report was reviewed by the finance team.
• Has your laptop ever been damaged by a power surge?

by vs. with

Use by for the person or thing that does the action. Use with for the tool or instrument that person uses.

by (who did it)	with (what tool was used)
The door was opened by the security guard.	The door was opened with a master key.

You can combine them:

• The lock was broken by someone with a crowbar.

Works Created by Someone

Use by to say who created a work (book, painting, piece of music, etc.).

• Have you read the latest report by the research department?
• That presentation by our CEO was really well done.

by = Next to / Beside

By can also mean “next to” or “beside.”

• The printer is by the window.
• Come and sit by me during the meeting.

by = Showing a Difference

Use by to describe the size of a change or difference between two things.

• Revenue increased by 12% this quarter.
• She missed the deadline by two days.
• Our team won the pitch by a narrow margin.

Quick Self-Check