Conditional Sentences Lesson - Definition, Types and Examples

Lesson Overview

• What Are Conditional Sentences?
• Types of Conditional Sentences
• Rules of Conditional Sentences
• Examples of Conditional Sentences

Conditional Sentences are an essential part of English that help express possibilities, outcomes, and relationships between actions. 

They allow us to describe what might happen, could have happened, or will happen under certain conditions.

What Are Conditional Sentences?

Conditional Sentences are sentences that describe actions or events dependent on a condition. These sentences help us discuss situations based on specific requirements or hypothetical scenarios.

These sentences typically consist of two parts: the condition (if-clause) and the result (main clause). The condition explains what needs to happen for the result to occur. 

For example, "If I had studied, I would have passed the test." 

Here, the result (passing the test) depends on the past condition of studying.\

Take this quiz :

Conditional Sentences Quiz: Test Your Grammar Skills

Types of Conditional Sentences

In English, there are four main types of Conditional Sentences, each expressing different situations and outcomes:

Zero Conditional Sentences

Zero conditional sentences describe facts or general truths, where the result is always the same whenever the condition is met. Both parts of the sentence are in the present tense, as the outcome is inevitable.

Examples:

• If you heat ice, it melts.
• When you add sugar to tea, it becomes sweet.

First Conditional Sentences

First conditional sentences refer to real or possible situations in the future. The condition is expressed in the present tense, and the result is shown in the future tense, indicating a likely outcome.

Examples:

• If you study hard, you will pass the exam.
• If it's sunny tomorrow, we will go to the beach.

Second Conditional Sentences

Second conditional sentences describe hypothetical or unlikely situations. The "if" clause is in the past tense, while the main clause uses modal verbs like "would," "could," or "might," indicating possible but unreal outcomes.

Examples:

• If I lived in Paris, I would learn French.
• If I were rich, I could travel the world.

Third Conditional Sentences

Third conditional sentences talk about past situations that didn't happen. They imagine alternate outcomes by using the past perfect in the "if" clause and modal verbs with "have" in the result clause.

Examples:

• If I had known about the event, I would have attended.
• If we had taken the earlier train, we could have arrived on time.

Rules of Conditional Sentences

These rules guide how to use tenses, punctuation, and structure effectively for each type of conditional.

1. Use the correct tense in both parts of the sentence
   The verb tenses used in the "if" clause and the main clause must align with the type of conditional sentence.
   • Zero Conditional: Both clauses use the present simple tense (e.g., "If it rains, the ground gets wet").
   • First Conditional: The "if" clause uses the present simple, and the main clause uses the future simple (e.g., "If it rains, we will stay inside").
   • Second Conditional: The "if" clause uses the past simple, and the main clause uses would + base verb (e.g., "If I had more time, I would travel").
   • Third Conditional: The "if" clause uses the past perfect, and the main clause uses would have + past participle (e.g., "If I had studied, I would have passed the test").

2. Use commas appropriately
   When the "if" clause comes first, use a comma to separate it from the main clause. If the main clause comes first, no comma is needed.
   • Example: "If I had studied, I would have passed the exam."
   • Example: "I would have passed the exam if I had studied."

3. Omit "if" in some cases
   In second and third conditional sentences, "if" can sometimes be omitted, especially in more formal structures. This is often called the "inversion" form.
   • Second Conditional: "Were I you, I would apologize."
   • Third Conditional: "Had I known, I would have helped."

4. Expressing unreal or hypothetical situations
   In second and third conditionals, we describe situations that are contrary to fact or unlikely. Always use the past simple (second conditional) and past perfect (third conditional) for unreal situations.
   • Second Conditional: "If I were rich, I would travel the world." (I am not rich.)
   • Third Conditional: "If I had known earlier, I would have called you." (I didn't know earlier.)

5. Use modal verbs in place of "will" or "would"
   Sometimes, instead of "will" or "would," other modal verbs like may, might, can, could are used to express different levels of certainty.
   • Example: "If you tried harder, you might succeed."

Example: "If I had known, I could have helped you."

Examples of Conditional Sentences

1. If you touch a hot stove, it burns your hand. (Zero Conditional)
2. If she finishes her homework, she will join us for the movie. (First Conditional)
3. If I owned a boat, I would sail across the ocean. (Second Conditional)
4. If we had saved more money, we could have traveled to Europe last summer. (Third Conditional)
5. If the alarm doesn't ring, you will be late for school. (First Conditional)