Conditional Sentences Definition, Types and Useful Rules

What are Conditional Sentences?

Conditional sentences are sentences used to express the idea that something is dependent on another—all conditional are composed of two sentences or clauses. The first clause expresses a condition, and the second part reveals what happens if that condition is met. This article explains the basic rules associated with conditional sentences and explores how to construct and use them in writing.
English Conditional Sentences Definition, Types and Useful Rules

Definition of Conditional Sentence

A sentence consists of two clauses the if clause that introduces the hypothesis (an assumption or condition) and the main clause that introduces the result is called a conditional sentence. For example: “If they play well, they might win.
A conditional sentence is introduced by the conjunction if/unless.
Both the clauses are separated with a comma when we place the if or conditional clause before the result or main clause. No comma is necessary when we put the result clause before the conditional or if clause.
If she does not study, she will not pass the exam.
OR She will not pass the exam if she does not study.
When we are sure about something to happen, we use when. To indicate that something might happen, we use if.
If I meet him tomorrow, I’ll talk to him about the problem. (This might happen)
I’ll talk to him about the problem when I meet him tomorrow.  (This will definitely happen)

Alternatives to If in a Conditional Sentence 

To talk about an imaginary situation, imagine that and suppose or supposing that can be used instead of ‘if. Other words used instead of ‘if’ are provided/providing, assuming, as long as, even if, on condition that, in the event of, in case.
  • Imagine that you were a doctor. Would you be glad?
  • Suppose he said no. what do we do then?
  • I will call him provided that I have time.
  • As long as he promises to work honestly, we can give him the job.
  • Unless he comes, I won’t leave the room.
  • The employees agreed to work until eight on the condition that they were paid overtime.
  • Take an umbrella in case it rains.
  • Unless and if not mean the same thing.
  • Unless you worked hard, you wouldn’t pass the exam.
  • Unless you worked hard, you would fail the exam.

When to Use Conditional Sentences?

There are several situations where we need to use a conditional sentence. The uses of conditional sentences include the following. 

Expressing Hypothetical Situations

  • If you didn’t take a map, you might get lost
  • If I had taken the pill, I would have been satisfied.

Making Polite Requests

  • Would you mind if you passed me the sugar?
  • Would it be possible if you could return my laptop?
  • Do you mind if you close the door?

Giving & Asking for Advice

  • If I were you, I wouldn’t drink so much beer.
  • I would go jogging if I were you.
  • If she were me, what would she do?
  • What’s your advice if I leave this paper?
  • What do you say if I take her to the doctor?
  • My father is overweight. He cannot lose weight. What do you say if he stops eating dinner?
  • If she takes our advice, she will go to the hospital.

Predicting Possible Outcomes

  • If you see his dog, you might be frightened greatly.

Expressing Uncertainty About Future Events

  • He’s likely to apologize to you if you meet him.
  • If it won’t rain today, the weather will probably be very hot tonight.

Asking for Confirmation About Something

  • Let us know if that product works for you.
  • If they don’t mind, I’d like to explain the rest of the topic again.

Negative Conditional Sentence

A conditional sentence is said to be negative if the condition described in the if-clause of a conditional sentence is not met; otherwise, it’s positive. For example: If you didn’t study hard for that exam, you wouldn’t pass it! Or even better: You would fail that test if you didn’t study hard enough!

Examples of Negative Conditional

  • If you don’t finish the work early, you won’t go home early.
  • If you don’t sleep, watch the movie.
  • Wash the dishes if you don’t cook the meal.
  • Men die if they do not eat.
  • If you spoke faster, we wouldn’t understand you better.
  • He wouldn’t have fallen ill if he hadn’t eaten more.
  • If your brother had not spent all the money, he would not ask me to lend him some now.
  • We’d have won the match if you had practiced well.

When to use will/would with if-clauses?

We usually never put will, would, and should with the if-clauses. But there is however some exception to these rules.
If + will/would
This structure is used as a formal expression, and this is not conditional for example
  • If you will, /would come with me please, I’ll show you my apartment.
  • If you will send me your documents, I’ll be able to apply for you. (=Will you, please send…polite request)
But using would instead of will is used for the more polite request.
To express the willingness of someone to do something if + will/would also be used. For example
  • If you will contact me, I’ll be able to guide you. (=If you are willing to contact me)
  • If my son would tell me what he wanted for school, I’d buy it for him. (=This means he is unwilling to tell me.)
If + would like/care is more polite than if + want/wish. For example
  • If they would like to go with us, we will book a ticket for them.
  • If you would care to watch the film, I’ll turn on the TV.

Variation of Tenses in Conditionals Sentences

We use different combinations to make conditional sentences. Some essential combinations of different tenses on conditional sentences are given below.
If/Conditional ClauseMain/Result Clause
If + Present SimplePresent Continuous
If + Present ContinuousPresent Simple
If + Past SimplePast Simple
If + Present ContinuousPresent Continuous
If + Past simplePresent Perfect

Types of Conditional Sentences

Conditional sentences are divided into four types the zerofirstsecond, and third conditional. This classification is based on how much something is probable to happen. Every kind of conditional sentence takes a different pair of tenses. Several variations are possible with each type of conditional sentence.

All the conditional sentences are really similar, but they aren’t the same. 

If ClauseMain ClauseType & Use
Present SimplePresent SimpleZero Conditional (Truth & Fact)
Present SimpleFuture Simple (Will + Infinitive)First Conditional (Possible)
Past SimplePresent Conditional (Would/Could + Infinitive)Second Conditional (Unlikely/Hypothetical)
Past PerfectPast Conditional (Would/Could have + PP)Third Conditional (Impossible)

The Zero Conditional (Type 0 Conditional)

The zero conditional describes real things, i.e., it describes truths and facts. The present simple tense is used in both the if-clause and the main clause.

If + present tensepresent tense.

  • When the sun shines, snow melts.
  • When I exercise, I feel relax.
  • When you drop a rock, it falls.
  • It gets improve if you study English grammar. 

The First Conditional (Type 1 Conditional)

This first conditional describes possible situations, i.e., it describes things that may or may not happen. The use of the first conditional is helpful when we think about what’s possible in the present or future. It uses the present simple in the if-clause and the present simple/future simple in the main/result clause.

  • If he works with honesty, he will get a promotion.
  • Make a sandwich if you are hungry.
  • If they do not call, we will leave without them.
  • I’ll be disappointed if they don’t send me a birthday card.
  • Unless he comes to school soon, I’ll call his parents.

The Second Conditional (Type 2 Conditional)

In the second conditional, we talk about things that are unlikely to happen or describe the situation that would happen in the future, which is the result of something that happened first. For the second conditional, we use past tense in the if-clause and would follow by the bare infinitive in the result clause.

If + Past + Would/Could or Might


  • If he tried to capture our house, we wouldtell the police.
  • We would come if they invited us.
  • would lend you the money if you needed it.
  • If I completed the study earlier tonight, I could play with you.
  • couldn’t go with them unless they wanted me to.

The Third Conditional (Type 3 Conditional)

The third conditional expresses imaginary situations. It takes the past perfect or past perfect continuous in the if-clause and would/could/might have + past participle in the result clause.

If + past perfect/past perfect continuous, would/could/might have + past participle.


  • If we had come earlier, we might not have missed the train.
  • If he had ridden the bike more carefully, he wouldn’t have been injured.
  • If we had lived in the 18th century, we might not have seen a cell phone.
  • If they had searched the internet well, they might have found helpful articles.
  • If the students had not been performing so poorly, the school wouldn’t have been lost the rank.
  • If my friends hadn’t come late, we could have watched the whole movie.

Note: A sentence is said to be conditional if it has two clauses, i.e., a conditional clause and a result clause. For example, the sentence, In summer it’s hot. It is not a conditional sentence because it doesn’t have two clauses.

Leave a Comment