What is the First Conditional?
The first conditional is a grammar structure used to talk about real, possible situations in the future. It shows the relationship between a condition (something that might happen) and its result (what will happen if the condition is true). We use the first conditional when we believe there is a real possibility that the condition will occur. It is the most common conditional form in English and is used for situations that are likely to happen.
The Basic Structure
The first conditional has two parts: the if-clause and the main clause. In the if-clause, we use the present simple tense. In the main clause, we use 'will' + base verb (the infinitive without 'to'). The structure is: If + present simple, + will + infinitive. You can also reverse the order: Will + infinitive + if + present simple. Both patterns are correct, but the if-clause usually comes first.
First Conditional vs Other Conditionals
| Aspect | Zero Conditional | First Conditional | Second Conditional |
|---|---|---|---|
| Form | If + present simple, present simple | If + present simple, will + base verb | If + past simple, would + base verb |
| When to use | Facts, general truths, and situations that are always true | Real and likely future situations; genuine possibility | Unreal, unlikely, or hypothetical present/future situations |
| Likelihood | Certain / always true | Possible / probable | Unlikely / imaginary |
| Positive example | If you heat water to 100°C, it boils. | If it rains tomorrow, I will take an umbrella. | If I won the lottery, I would buy a house. |
| Negative example | If you don't water plants, they die. | If she doesn't study, she won't pass the exam. | If he didn't work so hard, he wouldn't be so tired. |
| Question example | What happens if you mix bleach and ammonia? | Will you call me if you arrive late? | Would you travel more if you had more money? |
| Key signal words | always, generally, every time, never | tomorrow, soon, next week, tonight, probably | would, could, might, imagine, wish |
| Key Difference: The zero conditional describes universal truths that always happen; the first conditional focuses on real, plausible future possibilities where the outcome depends on a specific condition being met; and the second conditional deals with imaginary or highly unlikely scenarios. The clearest marker of the first conditional is the combination of present simple in the if-clause and will in the result clause, signalling that the speaker genuinely believes the situation could occur. | |||
Formula
✔ Positive
If
+
subject
+
present simple verb
+
subject
+
will
+
base verb
If you study hard, you will pass the exam.
✖ Negative
If
+
subject
+
present simple verb (negative)
+
subject
+
will not
+
base verb
If you don't hurry, you will miss the bus.
? Question
Will
+
subject
+
base verb
+
if
+
subject
+
present simple verb
Will you come if I invite you?
Examples
If it rains tomorrow, I will stay at home.
Real future possibility · Prediction
She will be happy if you give her the surprise.
Result-condition order · Likely outcome
If you mix red and blue, you will get purple.
General truth · Scientific fact
Will your parents let you go if you ask them nicely?
Question form · Seeking permission
If she doesn't call by 5 PM, we will leave without her.
Negative condition · Consequence
You won't succeed if you don't practise regularly.
Negative result and condition · Warning
When to use it
Making Predictions
Use the first conditional to predict what will happen if something occurs. These are things you think are likely to happen in the future.
"If you don't eat breakfast, you will feel tired at school."
Giving Warnings & Advice
Use the first conditional to warn someone about consequences or to give practical advice based on likely outcomes.
"If you touch that hot pan, you will burn your hand."
Discussing Plans & Arrangements
Use the first conditional when talking about future plans that depend on a condition happening first.
"If the weather is nice on Saturday, we will go to the beach."
Explaining Cause and Effect
Use the first conditional to explain how one action or situation will cause a specific result or consequence.
"If you study this chapter, you will understand the concept better."
Signal words
if
unless
as long as
provided that
in case
on condition that
will
might
may
when
Common Mistakes
✕
Wrong
If you will study hard, you will pass.
✓
Correct
If you study hard, you will pass.
Don't use 'will' in the if-clause. Use present simple, not future tense.
✕
Wrong
If you eat too much, you are feeling sick.
✓
Correct
If you eat too much, you will feel sick.
Use 'will' + base verb in the main clause, not present continuous or present simple.
✕
Wrong
If it rains, I stay home.
✓
Correct
If it rains, I will stay home.
The main clause needs 'will' to show a future result, not the present simple.
✕
Wrong
If you don't hurry, the shop will close before you arrive there.
✓
Correct
If you don't hurry, the shop will close before you arrive.
Avoid unnecessary words. Use the infinitive form after 'will', not a full clause.
KEY TAKEAWAYS
What to Remember
- Use the first conditional to discuss real, possible future situations with likely outcomes.
- The if-clause uses simple present tense; the main clause uses will + base verb.
- Both clauses can switch positions without changing meaning or grammar structure.
- The first conditional shows a real cause-and-effect relationship between condition and result.
- Don't use will in the if-clause; always use simple present tense there.