Mastering prepositions is one of the most important steps in learning English, and "in" is a key preposition of time that every student needs to understand. It connects to parts of the day, months, seasons, years, decades, and long periods of time. Let's break down exactly how and when to use it.
How do you use "in" with parts of the day?
The preposition "in" is used with three specific parts of the day [0:18]:
- In the morning.
- In the afternoon.
- In the evening.
You might wonder why "night" is not included. The reason is simple: these three parts refer to moments when there is still sunlight [0:42]. Night is a completely different period because there is no daylight at all. So whenever the sun is still out, you are talking about something that happens in the morning, in the afternoon, or in the evening.
What about seasons?
English has four seasons, and all of them use the preposition "in" [1:03]:
- In spring: flowers bloom.
- In summer: the weather is sunny and warm, perfect for going to the beach.
- In fall: holidays like Halloween and Thanksgiving are celebrated. Note that fall is the common word in North America, while autumn is also correct [1:24].
- In winter: activities like skiing are popular.
No matter which season you are referring to, "in" is always the correct preposition to use before it.
How do you use "in" with years and decades?
When you want to be specific about a year, place "in" right before it [1:47]:
- My sister was a teenager in 1985.
- I went to school in 2001.
- I traveled with my family in 2020.
Any year works as long as you include the preposition "in" before the number.
What is a decade and how do you express it?
A decade is a period of 10 years [2:06]. To refer to one, use "in the" followed by the short form of the decade:
- I used a corded phone in the '90s (the period from 1990 to 1999).
- My brother was born in the '70s.
- My parents got married in the '60s.
Notice how the article "the" appears before the decade, and the decade itself uses an apostrophe plus the number with an "s" at the end.
Why is "in" essential for time expressions?
Understanding the preposition "in" helps you communicate clearly about when something happens. It covers broad time references — from a single part of the day to an entire decade. The pattern is consistent: use "in" whenever you talk about mornings, afternoons, evenings, seasons, specific years, or decades.
Practice building your own sentences using each category. Try describing your daily routine with parts of the day, your favorite season, or an important year in your life. The more you use "in" in real sentences, the more natural it will feel. Download the worksheet mentioned in the lesson to keep practicing!
