First Conditional: Time Clauses (When, As Soon As, Before, After)

This grammar pattern uses two distinct parts. We call these "clauses." One part is the time clause. This part starts with a word like when or as soon as. The other part is the main clause. This is where the result or the main action lives. Here is the big secret. Even though both events happen in the future, we only use will in the main clause. The time clause stays in the Present Simple. It feels like you are standing in the future and looking at the clock. If you say, "When I will arrive, I will call," you are doubling up on the future. It sounds repetitive to native ears. Instead, we say, "When I arrive, I will call." The word when already does the heavy lifting of pointing to the future. It is a team effort. The time word sets the stage. The Present Simple keeps it grounded. The will clause delivers the punchline. It is a very efficient way to speak.

1. 1Building these sentences is like following a simple recipe. You just need to keep the tenses in the right bowls.
2. 2Start with your time word (like when, after, or before).
3. 3Add the subject and the Present Simple verb. This is your time clause.
4. 4Add a comma if you started the sentence with the time word.
5. 5Add the subject and will (or won't) + the base verb. This is your main clause.
6. 6Example: As soon as (Time word) + the meeting ends (Present Simple), + I will send (Future) + the notes.
7. 7You can also flip the sentence around. If the main clause comes first, you do not need a comma.
8. 8Example: I will send the notes as soon as the meeting ends.
9. 9Both ways are perfectly correct. Choose the one that feels more natural in the moment. Just remember: the will never, ever goes inside the part with the time word.

We use this pattern to talk about specific future plans and sequences.

• Use when for things you are sure will happen. "When I get home, I'll cook dinner." You know you are going home. It is a certainty.
• Use as soon as for immediate actions. This is for when you are in a hurry. "As soon as the taxi arrives, we'll leave." It means "immediately after."
• Use before to show which action comes first. "Before I sign the contract, I'll read it carefully." This is great for professional settings.
• Use after to show the second step in a process. "After I finish this project, I'll take a long nap."
• Use until to show a stopping point. "I'll stay at the office until I finish this report."

These words help you organize your life. They act like a calendar in your speech. They tell your listener exactly when things are going to happen.

Do not use this pattern for things that happened in the past. If you are telling a story about yesterday, use the Past Simple. "When I arrived yesterday, I called him." That is a different rule entirely. Also, avoid this pattern for general truths. If something is always true, use the Zero Conditional. "When it rains, the grass gets wet." This is a fact of nature, not a specific future plan. Finally, do not use this if you are expressing a polite request with if. While if and when look similar, they have different vibes. If is about a possibility. When is about a schedule. If you are not sure the event will happen, stick with if. If the event is definitely on the calendar, use when.

Yes, even native speakers mess this up sometimes, but usually only when they are tired! The most common mistake is the "Double Will."

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

✓ Correct: "When I see him, I will tell him."

Another mistake is forgetting the s for third-person subjects. Remember, it is still the Present Simple.

✗ Wrong: "As soon as he arrive, we will start."

✓ Correct: "As soon as he arrives, we will start."

Lastly, watch out for the comma. If the time word starts the sentence, the comma is your best friend. If the time word is in the middle, the comma needs to leave the party. It is like a grammar traffic light. The comma helps the reader pause at the right time.

How is this different from a normal First Conditional? A normal First Conditional uses if.

• If I see him, I'll tell him. (Maybe I will see him, maybe I won't. I am not sure.)
• When I see him, I'll tell him. (I am definitely going to see him. I am just waiting for the moment.)

It is also different from the Present Continuous for the future.

• I am meeting him at 5:00. (This is a fixed arrangement.)
• After I meet him, I'll go home. (This describes the sequence of events.)

Think of time clauses as the "sequencing" tool of English. They are less about "if" and more about "when." They help you build a timeline of future events.