The word “by” is very common in English. It can be used in lots of different situations and contexts. It is mostly used as a preposition but it can also in fact be used as an adverb. In this article, I explain the common uses of “by” as a preposition.

“by” + place

The meaning is: beside, at the side of, next to, close to

examples:

  • The house is by a river.
  • David lives by a train station.
  • I would love to live in a house by the sea.

“by” + method of transport

This structure describes how you travel somewhere.

by + train     car     boat     plane     taxi     bus     coach

examples:

  • David went to Manchester by train.
  • I go to work by car.
  • My parents often go to France by boat.
  • Our children have never travelled by plane before.

“by” + method of communication

This structure describes how you communicate with someone.

by + telephone     post     email     fax

examples:

  • I spoke to her by telephone.
  • I will send you the invoice by post.
  • Please confirm the order by email.

“by” + method of payment

This structure describes how you pay for something.

by + credit card     cheque

examples:

  • We paid for the computer by cheque.
  • Can I pay by credit card?

Note that we do not use “by” for cash payments. We use the preposition “in”:

  • David paid in cash for the newspaper.

It is also possible to omit the preposition completely, particularly in spoken English:

  • David paid cash for the newspaper.

“by” and the passive

In the passive voice, “by” indicates WHO is doing the action.

First, let’s look at a sentence using the active voice:

  • David is cleaning the kitchen.

In the above sentence, “David” is the person doing the action. When we convert this sentence to the passive voice, we say:

  • The kitchen is being cleaned by David.

Here are some more examples. These are in the past tense:

  • Sarah wrote the book. (active)
    The book was written by Sarah. (passive)
  • Our school organised the concert. (active)
    The concert was organised by our school. (passive)

“by” + reflexive pronoun

by + myself     yourself     himself, herself, itself     ourselves     yourselves     themselves

This structure means to do something alone.

examples:

  • I enjoy reading by myself.
  • Sarah is studying by herself.
  • Let’s do something by ourselves.
  • My parents often go on holiday by themselves.

“by” + -ING verb

This structure describes how to do something. It gives us more information about how to achieve a particular result.

example:

  • You can turn on the radio by pressing that button.

question:
How can I turn on the radio?

answer:
by pressing the button

The phrase “pressing the button” describes how to do something (how to turn on the radio).

“by” + time expression

The meaning of this structure is:  not later than; before or at a particular time

We use this structure for deadlines. A deadline is the time before which something must be done.

examples:

  • Guests must vacate their hotel rooms by 11 am.
  • Please send us the payment by tomorrow.
  • Students must enrol by the end of June.

sources : Original Link