When, before, after: Time conjunctions

These words connect two different parts of a sentence. We call these parts "clauses." One part is the main action. The other part tells us the time.

• When shows that two things happen at the same time.
• Before shows that Action A happens first, then Action B.
• After shows that Action B happens first, then Action A.

You can put these words at the start of a sentence. You can also put them in the middle. It is like a puzzle. The pieces fit together either way. However, the meaning stays the same. You just need to watch your punctuation. It is like a grammar traffic light. It tells the reader when to pause.

1. 1There are two main ways to build these sentences:
2. 2Starting with the time word:
3. 3[Time Word] + [Subject] + [Verb], + [Main Clause].
4. 4Example: Before I sleep, I read a book.
5. 5Starting with the main action:
6. 6[Main Clause] + [Time Word] + [Subject] + [Verb].
7. 7Example: I read a book before I sleep.
8. 8Notice the comma in the first pattern! If the time word comes first, you must use a comma. If the time word is in the middle, no comma is needed. It is a simple rule, but it makes your writing look much cleaner.

Use these words whenever you need to sequence events.

Ordering Food

Imagine you are at a busy cafe. You might say, "After I finish my coffee, I will order a croissant." This tells the waiter exactly what to expect. Or, "When the food arrives, can we have some napkins?"

Asking Directions

If you are lost in London, someone might tell you: "Turn left after you see the big clock." Or, "When you reach the park, stop walking." It helps you visualize the steps.

Job Interviews

You want to sound organized. "Before I started this role, I worked in sales." This shows a clear career path. "I always check my emails after I arrive at the office."

Daily Routines

"I brush my teeth after I eat breakfast." (Hopefully! Your dentist will thank you). "When I get home, I take off my shoes."

Do not use will immediately after these time words when talking about the future. This is the golden rule! Even if the whole sentence is about tomorrow, the part with when, before, or after stays in the Present Simple.

Wrong: When I will see him, I will tell him.

Right: When I see him, I will tell him.

Yes, even native speakers mess this up sometimes when they are tired. But in an exam or a formal email, it is very noticeable. Also, don't use these words if the timing is irrelevant. If you are just listing facts like "I like cats. I like dogs," you don't need time conjunctions.

The "Double Will" Trap

As mentioned, using will twice is a classic error.

✗ After I will graduate, I will travel.

✓ After I graduate, I will travel.

The Missing Comma

If you start with the conjunction, don't forget the comma. It helps the reader breathe.

✗ Before I go to bed I drink tea.

✓ Before I go to bed, I drink tea.

Confusing Before and After

This sounds silly, but in the heat of a conversation, people swap them.

✗ I wash my hands after I eat. (Wait, shouldn't it be before?)

✓ I wash my hands before I eat.

When vs. While

Use when for a single point in time. Use while for a long action that continues.

• When the phone rang, I jumped.
• While I was sleeping, the phone rang.

Before vs. Until

Before marks a point in time. Until marks the duration leading up to that point.

• Call me before 5 PM. (The deadline is 5 PM).
• Wait here until 5 PM. (Stay here for the whole time).