“In” to count from the present
When we are talking about something in the future and want to say how far it is from the present, we usually use the word “in” (not “later”).
✓ The meeting starts in five minutes. We’d better hurry, or we’ll be late!
✗ The meeting starts five minutes later. We’d better hurry, or we’ll be late!
Here are some more examples.
- Sorry, I can’t talk right now. Can I call you back in an hour?
- My report is due in three days, and I haven’t even started writing it yet!
- He just started tenth grade, so in three years he’ll graduate.
In all of these examples, we are counting time from the present. “In an hour” means one hour after the present, “in three days” means three days after the present, and so on.
“Later” to count from a past or future time
If we are not counting time from the present, but from some other point in time, we normally use “after” or “later” instead of “in.”
- William Henry Harrison became president on March 4, 1841, and died a month later.
- He met her when he was 18, and they got married five years later.
- It started raining at about 8:00 this morning, but it stopped an hour later.
In the examples above, “later” is being used to count from a past point in time. Harrison died one month after March 4, 1841 — in other words, on April 4, 1841. They got married five years after they met — that is, when he was 23. The rain stopped an hour after 8:00 — so it stopped at 9:00.
In the following examples, “later” is used to count from a future point in time.
- I have a math test next Wednesday and an English test two days later. (i.e., next Friday)
- We’ll take a short break at 3:00 and start the class again 10 minutes later. (i.e., at 3:10)
- I finish work at 5:00, and I’ll be home 20 minutes later. (i.e., at 5:20)
“In” to say how much time is needed
There’s another common use of “in” + time expression. We can use it to say how much time is needed to do something. This could be in the past or future, or in general.
- Roger Bannister was the first person to run a mile in less than four minutes.
- I have some things to do tomorrow, but they won’t take much time. I should be able to finish in about an hour.
- Puppies usually reach their adult weight in one to three years.
“Later” without a time expression
If we use “later” without a time expression, it just means “sometime in the future.” It doesn’t say exactly when. Usually the main meaning is “not now.”
- I don’t have time to wash the dishes now. I’ll do it later.
- I have to go now. Talk to you later.
I hope you’re finding these posts helpful. I’ll be posting another one in a few days. See you all later!
Eton Royal English School