Difference Between by and Until Examples and Exercise

When students get confused between the use of “by” and “until”. Both these words are related to time, but they cannot be used in the same way. In this article, I will explain the difference between by and until with examples, common mistakes, and exercise.

Table of Contents

What Is the Definition of By?

By (+ a time) = ‘not later than’.
By means that something happens by a time in the future.
Example Sentences:
I need the homework by Wednesday.
We have to be home by 6 o’clock.
The maid must clean the room by the afternoon.

What Is the Definition of Until?

Until is used to say how long a situation continues.
It means that something continues until a time in the future.
Example Sentences:
We waited until John came home.
Diane will be away until Friday.
I didn’t get up until 9 am.

What Is the Key Difference: By vs Until (Table)

Feature	By	Until
Shows	Refers to a completion date/deadline.	Refers to continuance up to a time.
Meaning	It means a time not later than.	It means something continues until a time in the future.
Example	Where is John? He should be here by now.	You will have to stay here until Monday.

Key Difference between by and until.

What Are the Common Mistakes While Using by and Until?

Let us look at the following sentences to identify the mistakes in it.

I will live here by 2030. (wrong)

I will live here until 2030. (right)

Explanation: Use ‘until’ in the above sentence as the person will live there up to 2030.

Finish the cleaning until 5 pm. (wrong)

Finish the cleaning by 5 pm. (right)

Explanation: Use ‘by’ because 5 pm is the deadline for completing the cleaning.

I will stay here by 9 pm. (wrong)
I will stay here until 9 pm. (right)

Explanation: Use ‘until’ because the task of staying there will continue till 5 pm.

Tips To Remember

Use by for deadlines.
Use ‘until’ for how long something lasts.
Note: If an action is finishing before a point of time, use by. If an action is continuing up to a point in time, use until.

Practice Exercise.

Use by or until in the following exercise.

The school is open ___________ 8 am.
He said that he would complete the project _______ 5 pm.
The will start the meeting ________ 9 am.
They will sit in the park ________ I come back.
_________ the end of the sports class, everybody was tired.
I will be practicing singing __________ I sing well.
Fiona promised to bring back my notebook ________ Tuesday morning.
Learning French was difficult ________ I came across this book.
I will write ________ 9 pm.
I will have to complete this book _________ Monday.

By understanding he difference between by and until one can become a confident speaker. It also helps you to improve your writing skills. They can speak about time in their daily lives easily.

Frequently Asked Questions

1. What is the main difference between by and until in English grammar?

By means not later than a particular time in the future. Example: I will wake up by 7 am.
Until means something will continue until a time in the future. Example: I will not go to school until you give me a chocolate.

2. Can I use by and until interchangeably?

No, we cannot use by and until interchangeably because by emphasizes the expected time to complete an action, while until refers to an action that continues and stops at a particular time in the future.

3. What are some common mistakes when using by and until?

Learners often confuse when they use by and until. For example, I will get ready until 6 pm. (wrong).
I will get ready by 6 pm. (right)
Explanation: It means that 6 pm is the specific time in the future when the action of getting ready will be complete.

Example: I will not go by my sister comes from school. (wrong).
I will not go until my sister comes from school. (right).
Explanation: It shows that the person will stay there until the action of her sister coming from school is completed.

4. How can I easily remember when to use by vs until?

Think of using by as a “deadline” (finishing time of an action before or at that time) and until as “duration” as an action that keeps continuing up to a specific time in the future.

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