Conditional Sentence


Conditional sentences are sentences that express factual consequences, or imaginary or hypothetical situations and their concerns. Complete conditional sentences contain a conditional clause (often denoted as the if-clause) and the consequence. Conditional sentences are statements conversing known factors or expected situations and their consequences. 

Conditional Sentences are also known as Conditional Clauses or If-Clauses.

Conditional tenses are used to guess or speculate about what might have happened, what could happen, and what we wish would happen. They are used to express that the action in the main clause (without if) can only take place if a certain condition (in the clause with if) is achieved. In English, most sentences using the conditional sentence contain the word "if". In many negative conditional sentences, there is an equal sentence construction using "unless" instead of "if".

In English grammar, imaginary sentences are called a conditional sentence –
  • We use conditionals to talk about imaginary situations in the past, present and future.
  • We use conditionals for actions in the past that cannot be changed.
  • We use conditionals for situations that might happen in the future or situations that might never happen.

Consider the following examples:
  • If I study, I will pass the exam.
  • If I had studied, I would have passed the exam.
  • If I had studied, I would not have failed the exam.

Types of Conditional Sentences 

There are four different types of conditional sentences in English Grammar. Each conditional type states a different degree of probability that a situation will occur or would have occurred in certain situations.
  1. Zero Conditional Sentences
  2. First Conditional Sentences
  3. Second Conditional Sentences
  4. Third Conditional Sentences

 Conditional sentence type   Usage   If clause verb tense   Main clause verb tense 
 Zero  General truth   Simple present  Simple present
 Type 1  A possible condition and its probable result   Simple present  Simple future
 Type 2  A condition impossible to fulfil or not really likely to happen in future.
A hypothetical condition and its probable result 
 Simple past
 Present conditional or 
Present continuous conditional
 Type 3 A condition not possible to fulfil (too late) or
An unreal past condition and its probable result in the past
 Past perfect  Perfect conditional
 Mixed Type  An unreal past condition and its probable result in the present  Past perfect  Present conditional

Let’s check each of these different types of conditional sentences in detail –

How to Use Zero Conditional Sentences

Zero conditional sentences express general truths—situations in which one thing always cause another. The zero conditional is used when the time being referred to is now or always and the situation is real and possible. When you use a zero conditional, you’re talking about general truth rather than a specific instance of something. Consider the following examples:

 If clause   Main clause 
       If + simple present         simple present 
 If it rains        the grass gets wet.     

Ex 1 – If you don’t brush your teeth, you get cavities.
Ex 2 – When people smoke cigarettes, their health suffers.

Note :
  • When using the zero conditional, the correct tense to use in both clauses is the simple present tense. A common mistake is to use the simple future tense.
  • Notice that the words ‘if’ and ‘when’ can be used interchangeably in the zero conditional sentences.
  • This is because the outcome will always be the same, so it doesn’t matter “if” or “when” it happens.

How to Use First Conditional Sentences

First conditional sentences are used to express situations in which the result is likely (but not certain) to happen in the future. The type 1 conditional is used to refer to the present or future where the situation is real.

  If clause                Main clause  
      If + simple present        simple future
 If you don't hurry        you will miss the bus.     

Ex 1 – I’ll go shopping on the way home if I have time.
Ex 2 – If it’s a nice day tomorrow, we’ll go to the beach.

  • We use the simple present tense in the if-clause and simple future tense in the main clause—that is, the clause that expresses the likely outcome.
  • Under a certain condition (as expressed in the if-clause), a specific result will likely happen in the future.

How to Use Second Conditional Sentences

Second conditional sentences are useful for conveying outcomes that are totally unrealistic or will not likely happen in the future. The type 2 conditional is used to refer to a time that is now or any time, and a situation that is unreal.

 If clause   Main clause 
 If + simple past             present conditional or present continuous conditional          
             If I spoke French              I would be working in France.

Ex 1 – If I bought a Ferrari, I would have no money left.
Ex 2 – If I were you, I would not be rude to the boss.

  • In the above example, someone is giving advice by imagining himself/herself in their position—”If I were you…”—and then telling them what he/she would do in their position.

How to Use Third Conditional Sentences

Third conditional sentences are used to explain that the present circumstances would be different if something different had happened in the past.

 If clause    Main clause  
              If + past perfect                     perfect conditional or perfect continuous conditional           
 If it had rained  you would have gotten wet.

Ex1 – If I had cleaned the house, I could have gone to the movies.
Ex 2 – If I had accepted that promotion, I would have been working in London.
Ex 3 – If you had eaten breakfast, you would have felt fine this morning.

  • The sentences express a condition that was likely enough but did not actually happen in the past.
  • These are all conditions that were likely but regrettably did not happen.
  • When using the third conditional, we use the past perfect (i.e., had + past participle) in the if-clause.

Mixed Type Conditional
The mixed type conditional is used to refer to a time that is in the past, and a situation that is ongoing into the present.

                           If clause   
 Main clause  
         If + past perfect or simple past         
  present conditional or perfect conditional
 If you weren't afraid of spiders          you would have picked it up and put it outside.         

Example: If we had looked at the map, we wouldn't be lost.

Conditional Sentence Rule

Mentioned below are a few Conditional Sentence Rules:

1. It’s important to use the correct structure for each of these different conditional sentences because they express varying meanings.

2. Pay attention to verb tense when using different conditional modes.

3. Use a comma after the if-clause when the if-clause precedes the main clause.

Conditional Sentence Examples

Let's check a few examples of Conditional Sentences:
  • If she’s sleeping, she won’t wake up until morning.
  • If you are coming with us, you would have a great time.
  • If the flight’s late, we’ll miss our connection.
  • If I’d realised you were going to be so sensitive, I’d have kept quiet.
  • Alan is going to post me the recipe if he finds it.
  • I’m sure my mother would help if you asked her.
  • The meeting would’ve finished before 12:00 if you’d said less.
  • If Shaila rings, I might ask her to come over for dinner.
  • He would buy a flat if he had the money for a deposit.
  • If they had left earlier, they would have arrived on time.
  • If you decided to take the exam, you would have to register by 31 March.
  • If the kids are enjoying themselves, we just let them go on playing till they’re ready for bed.