Learn to correctly use one of the most useful but complicated prepositions in English.
1. A Deadline
The first common use of “by” is when describing a deadline, which is the latest possible time for an action to happen. For example, if an airline company says that 6pm is the latest time that you can arrive for your 7pm flight, then 6pm is a deadline. In this case, you can say that you have to arrive by 6pm.
When “by” is used this way, it does not mean that something has to happen at exactly this time. It means that something has to happen at this time or before this time. You can arrive for your flight at 4pm, 4:30pm, 5pm etc. but you cannot arrive after 6pm.
In the examples below, the word ‘by” is telling us the latest time that something will happen:
We have to finish the project by October 26th. (we can finish it earlier than the 26th but not after)
The storm will be here for a few hours, but it should be gone by 8pm. (the storm will leave at 8pm or earlier)
If you want to apply for this job, you need to submit your application by Friday. (you can submit it earlier than Friday or on Friday, but not later than Friday)
2. A Method as a Gerund
The second common use of “by” is when it is combined with a gerund (a verb in -ing form) to describe the method for achieving something. It answers the question “how?”.
For example, if you say that you want to earn extra money, then someone will ask about your method of earning money by asking “how”? You can answer this with “by” and a gerund: “I’m going to earn extra money by working a second job.”
The combination of “by” + a gerund is used for goals and other results that you want. In the examples below, “by” and a gerund describe how a positive result is achieved:
You can lower your blood pressure by drinking less alcohol and by exercising more often.
Many companies attract customers by using famous celebrities in their advertisements.
People can reduce water consumption by taking shorter showers.
3. A Method as a Noun Word
The third common use of “by’ is with a noun to describe a method used to pass or transmit something. For example, if you send a birthday card to someone and the method of passing/transmitting it is the mail system, you can say: “I sent a birthday card to her by mail.”
The most common nouns that are attached to “by” in this case are methods of transportation (“bus”, “train”, “plane”) and methods of delivery (“mail”, “post”, “courier”):
· It’s faster to go by train than by bus.
· It’s a small island, so you can only get there by boat.
· People used to travel long distances by horse.
Note that in each example, there is no article. When you use “by”, it’s incorrect to use “a” or “the”, so “by a horse” is incorrect, but “by horse” is correct.
4. An Amount of Difference
The fourth common use of “by” is when describing the amount of change or difference between two things, usually with numbers. For example, if a price increased from $10 to $20, the amount of difference is $10 (100%) so you can say: “the price increased by 100%” or “the price increased by $10.”
In the examples below, the preposition “by” describes the amount of change:
The temperature outside changed by 20 degrees in just a few hours.
We lost our basketball game by 3 points. The final score was 80 – 77.
I wrote the test again and got a score of 88% this time. My score increased by 35%!
5. An Action Related to Passing Something
The final common use of “by” is when it’s combined with a verb of movement to describe passing something. You can just use the verb “pass” and say: “I passed your house” but if you want to use another verb like “ride” for your bicycle, then you can add the preposition “by”: “I rode my bicycle by your house.”
In the examples below, the preposition “by” is used with a verb to describe passing something:
We walked by the new library that they’re building. It’s going to be huge! (we passed the library by walking)
I drove by my old high school when I was back in my hometown. (I passed the high school by driving)
A huge bird flew by us when we were sitting in the park. I thought it wanted our food. (it passed us by flying)
Rewrite the underlined part of each sentence with “by” based on the uses of “by” mentioned in the lesson.
I learn how to fix things in my house, and my method is watching YouTube videos.
She won the election, and the difference was 300 votes.
You have to pay your taxes for last year, and the deadline is February 1st.
Whenever people pass an accident by driving, they slow down to look at it.
I already told him about it, and the medium that I used was text message.
I learn how to fix things in my house, by watching YouTube videos.
She won the election by 300 votes.
You have to pay your taxes for last year by February 1st.
Whenever people drive by an accident, they slow down to look at it.
I already told him about it by text message.