Difference between “By” and “Until” - Learn English Grammar

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Hi, everybody! My name is Alisha. Welcome

back to our EnglishClass Channel. Today we're gonna be talking about the

difference between "by" and "until." So let's get started!

Okay, so first we're gonna talk about "by." "By" marks a deadline for an action to finish.

"By" marks the point where an action completes or is replaced by another

action, so really think about using "by" to express a deadline; something is going to

stop, or you must finish an action at this point in time. So we can think about

"by" as marking some point in the future. So "by" mark some point in the future

where an action is going to finish, an action is going to be completed. So in an

example sentence I have, I'll be at the office by 7 pm.

So in this sentence, the

speaker is not at the office, but 7 pm is the deadline, this is the point in

time at which the speaker will be at the office. The speaker is not at the office now,

but by 7 pm, by the 7 pm deadline, the speaker will be at the office.

This "will" shows us this is a future tense expression, and "by" shows us the deadline,

the point at which that expression or the point at which that action is going

to be completed. So this is how we use "by," to think about it like a deadline at

some point in time at which an action will be completed or finished.

Okay, so let's continue on to the other grammar point for today, which is "until."

"Until" also has a more casual form, we can use "till" or " 'til". You might

see both spellings used for "until," till or 'til. In most cases, it's good to use "until."

In casual speaking and maybe in casual writing, you can use the casual form, but

"until" is always polite and is always correct. Okay, so when we use "until," let's

talk about when to use "until." We use "until" to talk about a continuing

situation or a continuing state now in the present or in the future, but it's

going to change or stop, so the key difference, one key difference here,

perhaps, is a continuing situation, a continuing state. With "by," the nuance is a

deadline something is going to finish at a deadline; here, however, "until" gives us

the nuance of something that's continuing, something true now, for

example, but that may not be true in the future. "Until" marks the point where that

action or that state is going to finish or change.

Okay, so we can think of it rather than as a deadline, as a key point in the

future, somewhere where action A continues until a point where we use

"until," and then a second action begins. Something is going to change at the

"until" point. With "by," however, we don't have the nuance of an action changing, we

only have the nuance of a deadline, so here "until" is used to show that

something different is going to happen, or something will finish but

there's going to be a change after the the "until" point. So, for example, this sentence,

very similar to the "by" example sentence, is: I'll be at the office until 7 pm.

So here we have the future tense, I'll, I will, I'll be at the office until 7 pm.

This sentence shows us the speaker is at the office right now,

however, at 7 pm, "until" shows us that 7 pm is the point at which the

situation or this state is going to change, so at 7 pm, the speaker is

probably going to leave the office. "Until" shows us that right here, the action or

the state is going to change, so please keep that in mind.

"Until" shows you a change in something; "by" shows more of a deadline for an action that is continuing.

So I hope that we can practice this in a few example sentences now. Okay!

So let's try to choose the correct word to use in these example sentences.

Should we use "by" or should we use "until" in these cases? So the first one I have is:

He has to find a new job ____ March.

So in this case, we see a point in time, we can think about it, should we use "by" or "until" here? If we use "by,"

we see that the deadline, the deadline nuance, matches here.

He has to find a new job by March.

If we use "until," he has to find a new job until March, there's no

information in this sentence that shows us a hint or that gives us a hint about

how the action is going to change. "Until" does not make sense for this question, so

we should use "by" in this case. He has to find a new job by March is the correct

answer for this sentence. In the second sentence,

I'm not going to go to bed ____ I finish this movie.

So in this sentence, we have, at the end, I finish this movie,

so there's some action, maybe that's continuing here, and we have

another action. I'm not going to go to bed, in this case, it's a negative, so

there are two actions here, this is a pretty good hint that there's an action

that's going to change at some point instead of the nuance of a deadline. So

for the sentence, "until" is the best answer.

I'm not going to go to bed until I finish this movie.

This shows us that at this point, the point where I finish the movie, I'm

going to go to bed. This marks the change in the continuing

state or the continuing situation. So the next sentence is:

They need to write their reports _____ tomorrow.

So this sentence, there's no change in the

sentence, we don't have any hints about some kind of different action that's

going to happen, instead we have maybe what seems to be a deadline, some

requirement here, too. So if we try to use "until" it doesn't make sense, there's no

changing action, we can't guess about what might happen in the future or a

change that might happen. So "by" is the best answer here.

They need to write their reports by tomorrow.

Tomorrow is the deadline.

So we can guess that tomorrow is the deadline here, "by" shows us that it's the deadline in this case

for this task. Alright! Let's take a look at something a little bit different. Here we have,

We can't leave the house ____ your mother calls.

So again there are two situations, there are two actions involved in this sentence.

we have "leave the house" and "your mother calls" (makes a phone call). So because there are two

actions here, we can guess that there's some change that's going to happen, so

because we learned that "until" marks a change in actions, we know that "until" is

the better answer here. Okay.

We can't leave the house until your mother calls

would be the correct sentence here. Alright! So let's look at the next

sentence though, this one is a tricky sentence, this one is a little bit difficult, we have:

I'm not going to be there ____ 8 pm.

So here we have 8 pm at the end of a sentence, which looks like a deadline, right?

We have going to be there.

So should we use "by" or "until" for this sentence?

It's difficult because, actually, both are okay for this sentence.

I'm not going to be there by 8 pm is correct, and

I'm not going to be there until 8 pm is also correct.

However, the meanings are very different. Just as we practiced in these two

sentences, I'll be at the office until, I'll be at the office by 7 pm,

the same is true here.

I'm not going to be there by 8 pm

means I'm not going to be there at 8 pm, it's not possible for me, I can't go.

However, I'm not going to be there until 8 pm, this sentence means,

after 8 pm, or beginning at 8 pm and after, I'm going to be there. So please, be careful.

In some cases, both "by" and "until" are correct but they change the meaning

of the sentence. Okay, let's continue to another example.

So the next example sentence is also a little bit difficult, it's:

If my date doesn't arrive ____ 7 pm, I'm leaving.

Okay, so here, we have, we do have two actions, "doesn't arrive," my date doesn't arrive, a

negative point, and "I'm leaving." So it seems like there are two actions here.

However, we have this 7 pm, this marks a deadline, right? So if my date doesn't

arrive, there's some deadline here, if this is not completed, something is going

to happen, the person is going to leave. So in this case, 7 pm is showing a

deadline, so we have to use "by."

If my date doesn't arrive until 7 pm.

We could use that, but it doesn't sound so natural, so the nuance, again,

here is of a deadline, there's something that is going to happen at 7 pm.

7 pm marks the endpoint in this situation, so we use "by" here.

Okay, let's go to the next pair, again, these are very interesting points.

We have to leave the beach ____ 10 am. And, we have to stay at the beach ____ 10 am.

Okay, so these two sentences, I included because I

wanted to show the emphasis of changing actions and continuing actions, so we can

see the verbs are different here. In the first sentence, we have "leave" so this is

a change, leaving a location; in the second sentence, I have "stay" which shows

a continuing action, stay in one place. So here, as you can guess then,

We have to leave the beach ____ 10 am.

Some change, some deadline, so we'll use "by" to show our deadline.

In the second sentence, we have to stay at the beach, stay shows a continuing action,

and then it's going to finish here, so we'll use "until."

we have to stay at the beach until 10 am.

This shows us a continuing action, and maybe at 10 am we'll leave the beach.

Alright! Let's go on to the next sentence.

I'm not going to travel abroad ____ I learn English.

Okay, so here there's no time point, there's no 10 am, 8 pm, tomorrow, and so on, so this is a

little more complex, maybe. We have "travel abroad" and "learn English," so it seems

there's no real deadline here, but we have, maybe, a change, maybe this shows us

some kind of change. Learning English marks a change.

So, I'm not going to travel abroad until I learn English.

This shows us that something different is going to happen in the future, so we should use "until" to

mark that change. Okay, our last example sentence for today is,

We told him to wake up ____ 6 am.

So, once more, our last sentence may be a little bit simple, but 6 am shows us an action, sort of this

deadline, you can see a lot of these use a time to mark a deadline for an action.

So here, we told him to wake up by 6 am.

This is the point at which something

must happen, so we should use "by."

Ok! Great! So those are a few examples sentences that you can have a look at and think about

when you're trying to decide whether to use "by" or "until." Keep in mind, however, there are some cases

where both "by" or "until" are correct, but the meaning is going to change

significantly depending on the one you use. So I hope this lesson was useful for

you, if you have any questions or if you want to try to make an example sentence

using"by" or "until," please be sure to leave us a comment. If you liked this

video, too, please be sure to hit the thumbs up and subscribe to our channel if you

haven't already. Thanks very much for watching this episode, and we will see

you again soon. Bye!