Zero, First, Second, & Third Conditional Sentences

Zero, First, Second, Third, & Mixed Conditional Sentences in English Grammar

conditional sentences in English Grammar

What are conditional sentences?

A conditional sentence is based on the word ‘if’ and its possible outcome. Conditional sentences are important in the English language since they assist us with communicating things that might occur in the present and future. Conditionals fill many needs and take a few unique structures. They are used to offer guidance, express emotions and examine realities, in addition to other things. Linguistically, the types of all conditionals appear to be unique; however, they generally share two provisions practically speaking. A statement is a piece of a sentence that contains a subject and action word. In restrictive sentences, there are two statements: the If Clause and the Main Clause (some of the time called the Result Clause).

Structure of Conditional Sentences:

The structure of conditionals is very simple. As a rule, conditionals consist of two parts –the if part (or the conditional part) and the main part (that describes possible/ultimate result). The order of these two parts of the conditional is not important but in first case, we place a punctuation mark (generally comma) to separate two parts.

There are two basic possibilities.

If condition + possible/ultimate result


Possible/ultimate result + if condition

To understand the conditional, read the sentences: If I catch a fast train, I will arrive in time. Or I will arrive in time if I catch a fast train.


Types of Conditional Sentences

There are five types of conditional sentences in English grammar and you need to be able to use and identify all of them.

The five types of main conditional are:

  1.   Zero conditional sentences:  

Zero condition (real condition | certain result)

  1.   First conditional sentences:  

Open condition (Possible condition | probable result)

  1.   Second conditional sentences:  

Half open condition (hypothetical condition | possible result)

  1.   Third conditional sentences:

Closed condition (Expired past condition | Possible past result)

  1.   Mixed conditional sentences:

(Impossible past situation | result in future)


Zero Conditional Sentences

The zero conditional sentences communicate something as a generally accepted fact, scientific/universal truth. We also use zero conditional sentences when one activity generally follows another. It is the simplest form of conditionals in English grammar. In zero conditionals, the outcome is certain.

In zero conditionals, the possibility of condition is 50% or above and the result (certainty of possible outcome) is 100%. Zero conditional sentences are some known as factual conditional when the condition and result are scientific or universal truth.

When there is a universal/scientific fact/truth, both parts of the conditional will be in present form.


If (or when) + current state | current state (outcome/result)


If you cut off oxygen, the flame dies.

When the sun sets, the night starts.

If you walk in the rain, you get wet.


When there is a generally accepted fact, both parts of the conditional can be in past form.


If (or when) + past tense | past tense (outcome/result)


My mother hugged me when I got frightened.

If you blend black and white, you get a gray color.


In Zero conditionals, the conditional word ‘if’ can be replaced by ‘when’.


When you heat water, it evaporates.

It gets dark when clouds cover the sky.



First Conditional Sentences

The first conditional sentence communicates a future situation that may happen. Expecting that the condition is satisfied, the result is probably going to occur.


If + current state | will (may/might/can/could/ought to) + infinitive

Example of First conditionals:

 If I wake up early today, I will go home.

If Jack passes the exam, he might be happy. 

We could fly in the air if we had wings like birds. 

If they struggle hard, they can win the game. 

 If she sees the loin, she may fall due to fear

He should drink a glass of water if he is thirsty. 


Second Conditional Sentences

Generally, the second conditional looks similar to first conditionals in meaning but their structure is very different. Moreover, the first conditionals usually refer to future events that are likely to happen, while the second conditionals refers to events that are unlikely to happen (or current impossibilities).


If + past subjunctive | could/might/would/can + infinitive (simple or continuous)

If + simple past | could/might/would/can + infinitive (simple or continuous)

Examples of Second Conditionals

If I were a bird, I would fly over the dales.

If he could dive faster, he might reach the airport by sunset.

She might be able to read a newspaper if she joined school.

If she boiled water, she would be able to boil eggs.

If John played music, he might be a rich person.


Third Conditional Sentences

The third conditional sentence communicates what is going on in the past, with reference to the hypothetical outcome that would result also in the past.


If + past perfect subjunctive | could/might/would + perfect infinitive

if + past perfect | could/might/would + perfect infinitive

Examples of third conditionals:

If I had known that the train is too slow, I would never start journey.

If she had seen the snake, we could not have walked a single step.

She might have cooked the rice, if she had woken up early in the morning.


However, the results of second and third conditionals refer to impossibilities but there is a little difference. The second conditionals refer to impossibilities in the present (“If I were you…”), while the third conditional refers to impossibilities in the past.


Mixed Conditional Sentences

As the name suggests, mixed conditionals use different parts of the above-mentioned conditionals. When we combine the second and third conditional in one sentence to make a hypothesis about the past that has a consequence in the present; we call it mixed conditional. In mixed conditionals, the condition is uncertain but the result is certain.

Structure of mixed conditional:

If + past perfect | would + verb / could + verb


If Raza worked harder in exams, he would have a good job now.

If we have looked at the screen, we would be aware of Corona.

If you were not afraid of loins, we would have visited the jungle many times.



Hope, you have understood all the conditional sentences. Now start practicing by using them on your own. Make some of your own sentences and change them to different conditional. Practice makes a man perfect

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