What are Conditional Sentences? – Definition & Examples

Conditional sentences are such if-sentences that consist of a dependant and an independent clause; and that are used to express a condition. It can not only help to express a condition, but can also help in expressing the outcome of that condition.

In most of the cases, you will find out that the conditional sentence begins with the subordinating conjunction ‘if’; or it is the dependant clause that starts with ‘if.’

However, it does not mean that a conditional sentence always start with a dependant clause that begins with ‘if’.
Take a look at the examples below,

1. If I lose some weight, I can climb a mountain.

                                        Or

• I can climb a mountain if I lose some weight.

In the above example sentences, the dependant clause begins with ‘if’ (if I lose some weight) whereas, the independent clause is ‘I can climb a mountain.’

Note: Some conditional sentences may also begin with ‘when.’

Different Types of Conditional Sentences

There are four different types of conditional sentences. Each type can help in expressing the probability or possibility of an action.

Let us discuss these types one by one.

Zero Conditional Sentences

Zero conditional sentences express truths or facts.

Remember the following rules for a zero conditional sentence,

• Start the dependent clause with ‘if’ or ‘when.’
• Always use simple present tense in both dependant and independent clauses.
• These sentences should be simple to express general truths.

Example sentences

1. If I don’t add sugar, dessert gets tasteless.
2. If you use mobile a lot, your eyes damage.
3. When you drink too much water, it results in water intoxication

First Conditional Sentences

A first conditional sentence expresses such an event or action that has the possibility to be happening in the future (but there is no guarantee for such a future happening.)

Remember the following rules for a first conditional sentence,

• Start the dependant clause with ‘if.’
• Use simple present tense in dependant clause and the simple future tense to express the outcome i.e. in the independent clause.

Example sentences

1. If students pay good attention on lectures, they will get good grades.
2. If you go out for a long drive, you will feel much better.
3. They will go out if he enters.

Second Conditional Sentences

A second conditional sentence expresses such an event or action that has no possibilities to happen in the future because that event or action is not real.

Remember the following rules for a second conditional sentence,

• Start the dependant clause with ‘if.’
• Use simple past tense in dependant clause and an auxiliary modal verb (i.e. could, would, might, etc.) in the independent clause to express the unreal outcome.

Example sentences

1. If I were the principal, I would cancel the examination.
2. If I owned this area, I would build a mall here.

Third Conditional Sentences

A third conditional sentence also based on an unreal event. It is used to express a past event or action that did not happen in the past. In simple words, these sentences could tell you an imagined result.

Remember the following rules for a second conditional sentence,

• Start the dependant clause with ‘if.’
• Use past perfect tense in the dependant clause and an auxiliary modal verb with ‘have’ (i.e. could have, would have, etc.) and a past participle verb in the independent clause to express the imagined unreal past event.

Example sentences

1. If I had attended the lectures, I would have passed the examination.
2. If I had gone earlier, I could have attended the ceremony.

Note: Commas should come after the dependant clause. If the dependant clause comes after the independent clause, there is no need to put a comma.

Real vs. Unreal Conditionals

Real conditionals (zero and first conditionals) describe factual or likely events that could happen in the present or future. Unreal conditionals (second and third conditionals) describe hypothetical, imaginary, or impossible situations, often in the past or future.

Real Conditional (First Conditional): If it rains, we’ll stay inside. (This describes a likely future event.)

Unreal Conditional (Second Conditional): If it rained, we would stay inside. (This describes a hypothetical situation that isn’t happening right now.)

The key distinction between real and unreal conditionals lies in the tense of the verb. In real conditionals, present or future tenses are used to indicate a possibility, while in unreal conditionals, past tense or past perfect is used to express an imaginary situation. For example:

Real (Zero Conditional): If you heat water, it boils. (A general fact.)

Unreal (Third Conditional): If I had known, I would have helped. (An impossible scenario because the time has passed.)

Common Mistakes in Conditional Sentences

Many learners make mistakes when constructing conditional sentences by using incorrect verb tenses or mixing up conditional types.

Mistake: If I will go, I will tell you.
Correction: If I go, I will tell you.
(Explanation: The “if” clause should use the present tense, not the future tense, even when referring to future events.)

Mistake: If I would have seen him, I would have said hello.
Correction: If I had seen him, I would have said hello.
(Explanation: The past perfect tense is required in the “if” clause for third conditionals that refer to past unreal events.)

Use the present tense in the “if” clause of real conditionals, even when discussing future events (first conditional).

What Did You Learn?

Conditional sentences have three different types. They are zero conditional, first conditional, second conditional, and third conditional sentences. They are also known as if-sentences that consist of a dependant and an independent clause and are used to express conditions or the outcomes.