Exercise 1
Choose the correct verb form to complete each first conditional sentence.
Example: If it rains tomorrow, we (stay / will stay) at home.
Answer: If it rains tomorrow, we will stay at home.
First Conditional in English
The first conditional is used to talk about real situations in the future. We use it when something is possible — it might really happen. For example, if the weather is good, you might go to the park. If you study, you might pass the test.
The first conditional connects two ideas: a condition (something that must happen first) and a result (what will happen because of it).
Here is a simple example:
If it rains, I will stay at home.
This means: Maybe it will rain. If that happens, I will stay at home. The rain is the condition. Staying at home is the result.
In this lesson, you will learn how to build first conditional sentences step by step.
First Conditional: Rule Breakdown
A first conditional sentence has two parts. We call them the if-clause and the main clause.
- The if-clause is the condition. It tells us what must happen first.
- The main clause is the result. It tells us what will happen.
The Pattern
If + present simple, will + base verb
Let us look at the two parts separately.
Part 1: The If-Clause (The Condition)
In the if-clause, we use the present simple tense. The present simple is the basic form of the verb. For example: rain, study, eat, go, feel, work.
Remember: even though we are talking about the future, we do not use "will" in the if-clause. We use the present simple.
If + subject + present simple verb
Examples of the if-clause:
If it rains…
If she studies…
If they are late…
If I feel better…
Part 2: The Main Clause (The Result)
In the main clause, we use will + the base verb. The base verb is the simple form of the verb with no endings — for example: go, eat, call, be, stay, help.
Subject + will + base verb
Examples of the main clause:
… I will stay at home.
… she will pass the exam.
… we will miss the bus.
… I will call the doctor.
Putting the Two Parts Together
If + present simple, will + base verb
If it rains, I will stay at home.
If she studies, she will pass the exam.
If they are late, we will miss the bus.
If I feel better, I will call the doctor.
Notice the comma (,) between the two parts when the if-clause comes first. This is important!
First Conditional: Full Examples Table
| If-Clause (Condition) | Main Clause (Result) | Full Sentence |
|---|---|---|
| If it is sunny | we will go to the beach | If it is sunny, we will go to the beach. |
| If you eat too much | you will feel ill | If you eat too much, you will feel ill. |
| If he calls me | I will answer | If he calls me, I will answer. |
| If she misses the train | she will take a taxi | If she misses the train, she will take a taxi. |
| If they work hard | they will finish on time | If they work hard, they will finish on time. |
| If we are hungry | we will cook dinner | If we are hungry, we will cook dinner. |
| If I save money | I will buy a new phone | If I save money, I will buy a new phone. |
Can We Change the Order?
Yes! The two parts of a first conditional sentence can change places. The meaning stays the same.
Look at these two sentences. They mean the same thing:
If it rains, I will stay at home.
I will stay at home if it rains.
When the if-clause comes first, we use a comma between the two parts.
When the main clause comes first, we do not use a comma.
| If-Clause First (use a comma) | Main Clause First (no comma) |
|---|---|
| If it rains, I will stay at home. | I will stay at home if it rains. |
| If she is tired, she will go to bed. | She will go to bed if she is tired. |
| If they study, they will pass. | They will pass if they study. |
Contractions in the First Conditional
In spoken English and informal writing, we often use contractions. A contraction is a short form of two words joined together. For example, will not becomes won't.
Here are the most common contractions with will:
| Full Form | Contraction | Example |
|---|---|---|
| I will | I'll | If it rains, I'll stay at home. |
| you will | you'll | If you study, you'll pass. |
| he will | he'll | If he calls, he'll leave a message. |
| she will | she'll | If she is late, she'll take a taxi. |
| it will | it'll | If it is cold, it'll snow. |
| we will | we'll | If we hurry, we'll catch the bus. |
| they will | they'll | If they win, they'll be very happy. |
| will not | won't | If you don't eat, you won't feel well. |
Negative Forms in the First Conditional
We can also make the if-clause or the main clause negative. To make a sentence negative, we use don't / doesn't in the if-clause, and won't (will not) in the main clause.
Negative If-Clause
Use don't or doesn't to make the condition negative.
If you don't hurry, you will miss the bus.
If she doesn't eat, she will be hungry.
If they don't study, they won't pass the exam.
Negative Main Clause
Use won't (will not) to make the result negative.
If it rains, I won't go to the park.
If you are rude, they won't help you.
If he is late, she won't wait.
Important Differences and Special Cases
First Conditional vs. Zero Conditional
At this level, you might also see the zero conditional. It looks similar, but it is different.
- The zero conditional talks about things that are always true — facts and general truths.
- The first conditional talks about things that are possible in the future.
| Type | Pattern | Example | Meaning |
|---|---|---|---|
| Zero Conditional | If + present simple, present simple | If you heat water, it boils. | Always true (a fact) |
| First Conditional | If + present simple, will + base verb | If it rains, I will stay at home. | Possible in the future |
Do Not Use "Will" in the If-Clause
This is one of the most important rules. We never use will in the if-clause of a first conditional. We always use the present simple there.
❌ If it will rain, I will stay at home.
✅ If it rains, I will stay at home.
Using "When" Instead of "If"
Sometimes we can use when instead of if. We use when for things we are more sure will happen.
If I see her, I will say hello. (Maybe I will see her — I am not sure.)
When I see her, I will say hello. (I am sure I will see her.)
The grammar pattern is the same: when + present simple, will + base verb.
Common Mistakes
❌ If it will rain, I will stay at home.
✅ Use the present simple in the if-clause: If it rains, I will stay at home.
❌ If she study hard, she will pass.
✅ Add -s for he/she/it: If she studies hard, she will pass.
❌ If I am hungry, I will ate something.
✅ Use the base verb after "will": If I am hungry, I will eat something.
❌ If it rains I will stay at home.
✅ Use a comma when the if-clause comes first: If it rains, I will stay at home.
❌ I don't go out if it will be cold.
✅ Use the present simple in the if-clause: I won't go out if it is cold.
❌ If you not hurry, you will miss the bus.
✅ Use don't/doesn't for negatives in the if-clause: If you don't hurry, you will miss the bus.
First Conditional: Quick Summary
The first conditional is used to talk about real and possible situations in the future.
- The pattern is: If + present simple, will + base verb
- The if-clause uses the present simple — never "will".
- The main clause uses will + base verb.
- Use a comma when the if-clause comes first.
- We can also use contractions: I'll, you'll, won't, etc.
- We can use don't / doesn't in the if-clause to make it negative.
- We can use won't in the main clause to make it negative.
- We can change the order of the two parts. The meaning stays the same.
| Part | Tense Used | Example |
|---|---|---|
| If-clause (condition) | Present simple | If it rains… |
| Main clause (result) | will + base verb | …I will stay at home. |
Now practise the first conditional in the exercises below.
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