Conditional sentences are one of the trickier parts of learning English. There are 5 types of conditional sentences, and you need to be able to use and identify all of them.
As a rule, conditional sentences in English consist of two parts – the main part and the if part (or the conditional part).
These types of sentences are used to express possible or imaginary situations.
The order of these two parts of the sentence isn’t important.
When written, if the if part of the sentence comes first, a comma should be used to separate it from the second part.
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5 Types of conditional sentences
Before we get started, here’s a brief chart summarizing the 5 types of conditional sentences and how they’re used:
Conditional sentence type | When to use | Main clause | If-clause |
Type Zero | Describing known facts | Simple present | Simple present |
Type 1 | A possible situation and the result | Will + infinitive | Simple present |
Type 2 | A hypothetical condition and its possible result | Would + infinitive | Simple past |
Type 3 | An impossible past situation and its result in the past | Would + perfect infinitive | Past perfect |
Mixed Conditionals | An impossible past situation and its result in the present | Past perfect | Present conditional |
Type zero conditional sentences (zero condition)
This type of conditional sentence is used to describe scientific facts, generally known truths, events and other things that are always true.
I think it’s the simplest type of conditional sentence in English.
The structure of Type Zero conditional sentences:
Main part: Present Simple; if part: Present Simple
Examples:
- Water boils if you heat it to 100 degrees Celsius.
- A red light comes on if you press the main button.
In Type Zero sentences, if can be replaced by when.
Examples:
- When you heat ice, it melts.
- It gets dark when the sun goes down.
Type One Conditional Sentences (open condition)
This type of sentence expresses real and possible situations in the future; it is possible for the condition to be met.
The structure of Type One conditional sentences:
Main part: will + infinitive; if part: Present Simple
Examples:
- We will stay at home if it snows.
- She will get angry if I‘m late for the party.
- If we get the money for this job, we will buy a new car.
- Will you help Amanda if she asks you?
Type two conditional sentences (half-open condition)
This type of conditional sentence describes an unreal situation with regard to the present or future; a hypothetical condition that can only be fulfilled in theory.
The structure of Type Two conditional sentences:
Main part: would + infinitive; if part: Past Simple
In conditional sentences, the past tense form of the verb to be is were for all persons; was is also used, although only in spoken or conversational English.
Examples:
- We would stay at home if it snowed.
- I would buy a new board if I had more money.
- If he were rich, he‘d buy an island.
- If you left now, you‘d catch the last bus.
Type two conditional sentences are also used when making polite requests.
Examples:
- I would be grateful if you helped me.
- He would be so pleased if you came to the birthday party.
The phrases If I were you or If I were in your place are usually used to give advice.
Examples:
- If I were you I would accept the offer.
- If he were in your place he would do it.
Type three conditional sentences (closed condition)
Type three conditional sentences are used to express situations that cannot exist, such as actions or events that happened in the past. They are often used to indicate a missed opportunity.
The structure of Type Three conditional sentences:
Main part: would + perfect infinite; if part: Past Perfect
Examples:
- If you hadn’t been late for work, the boss wouldn’t have gotten furious.
- They would have finished earlier if the meeting hadn’t been held so late.
- If I had won the lottery, I would have bought a house by the sea.
- Would you have helped me if I had asked you?
Mixed Conditionals
This type of conditional sentence uses (mixes) different parts of the above-mentioned conditional sentence types.
There are a few combinations: the condition emphasizes the result of the action in the present in the past tense, or the present-day condition emphasizes the result of the action in the past.
Examples:
- If you had taught me how to make waffles (in the past), I wouldn’t have to buy them in a shop (now).
- I would buy a house by the sea (now or in the future) if I had won the lottery last week.
- Their team would have scored more in the match yesterday if they were good players.
Important grammatical notes
If the modal verbs can/could, may/might or should are used in the main part of the sentence, they take the place of will:
- We can go to the seaside if you have time tomorrow.
- If you leave now, you may catch the last bus.
- If you want to pass the exam, you should study much harder.
The words will and would are not usually used in the if part, except when they express willingness, for example, in requests (that is, when they carry a modal meaning):
- If you will phone the manager now, he will surely make an appointment with you. (willingness)
- I would be very thankful if you would help me with my homework. (very polite request)
The word should in the if part can mean “if perhaps” or “by any chance.”
- I would be very happy if he should turn up at the party. (He’s not at all likely to come, but perhaps…)
In negative sentences, if…not can be substituted with unless.
- You won’t pass the exam unless you study very hard. (= if you don’t study very hard)
If can be omitted from the sentence if the word order is changed. This is sometimes done in Type Three conditional sentences if the, if part is at the beginning of the sentence, or in Type Two sentences if the verb were, is used:
- Were I rich, I would buy a house by the sea. (= if I were rich)
- Had your cousin come earlier, I would have shown her around the house. (= if she had come earlier)
I hope that my explanation of conditional sentences in English was clear and understandable.
If not, let me know!