First Conditional

In this lesson, you will learn how to use the first conditional to talk about a possible future situation and its result.

1. What Is the First Conditional?

The first conditional is used for real or possible future situations and their results.

It links a possible condition to its likely result:

possible future condition → likely future result

For example: If it rains tomorrow, we will stay at home. Rain is possible, and staying at home is the result.

2. Structure of the First Conditional

Structure: If + present simple, ... will + base verb; or will + base verb + if + present simple.

Use a comma when the if-clause comes first.

Examples:

• “If it rains tomorrow, we will stay at home.”
• “If I finish my homework, I will watch TV.”
• “If she studies hard, she will pass the test.”
• “If the weather doesn’t improve, we won’t go out.”

You can also change the order:

• “We will stay at home if it rains tomorrow.”

Questions

Use will + subject + base verb for yes/no questions, or put a question word first:

• “Will you come if I invite you?”
• “What will you do if it rains?”

3. Common Uses of the First Conditional

We use the first conditional for real future possibilities in specific situations.

A. Real future possibilities

• “If I have time, I will visit my friend.”
• “If the bus is late, I will be late for school.”

B. Warnings and likely results

• “If you touch that, you will hurt yourself.”
• “If you don’t study, you will fail.”

4. Other Forms in the Main Clause

Will is common in the main clause, but it is not the only possible form. We can also use other modal verbs or an imperative.

• can for ability or possibility: “If we leave now, we can catch the bus.”
• can in the negative: “If we do not leave now, we cannot catch the bus.”
• may / might for a less certain result: “If traffic is heavy, we might be late.”
• may / might in the negative: “If traffic is heavy, we might not arrive on time.”
• should for advice: “If it rains, you should take an umbrella.”
• should in a question: “If I feel ill, should I call the doctor?”
• an imperative for an instruction: “If you see Maya, tell her to call me.”
• a negative imperative: “If you are not sure, do not open the door.”

5. Using 'Unless'

Unless means if ... not. We can use it instead of an if-clause with a negative verb.

• “We’ll be late unless we leave now.” (= We’ll be late if we don’t leave now.)
• “Unless you hurry, you’ll miss the bus.” (= If you don’t hurry, you’ll miss the bus.)

If or when?

Use if when the condition is uncertain. Use when when you expect it to happen:

• “If I see her, I’ll tell her.” (Perhaps I will see her.)
• “When I see her, I’ll tell her.” (I expect to see her.)

6. Zero vs First Conditional

The zero conditional describes a general fact or repeated result. The first conditional describes one real or possible future situation.

Conditional	Use	Structure	Example
Zero	facts, habits, and results that are always true	present simple + present simple	“If you press the button, the light turns on.”
First	a specific, possible future situation	present simple + will/modal/imperative	“If you press the button tomorrow, the light will turn on.”

The word tomorrow makes the second example a specific future situation rather than a general fact.

7. Common Mistakes

Do Not Normally Use 'will' in the If-clause

Use the present simple after if, even when the condition is about the future.

• ✗ “If it will rain tomorrow, we will stay home.”
• ✓ “If it rains tomorrow, we will stay home.”

Use the Base Verb after 'will'

• ✗ “She will passes the test.”
• ✓ “She will pass the test.”

Do Not Add 'not' after 'unless' with the Same Meaning

• ✗ “Unless you don’t hurry, you’ll miss the bus.”
• ✓ “Unless you hurry, you’ll miss the bus.”