Conditional

Zero Conditional if + present ==> present

Expresses general truths and scientific facts. Used to show an evidence, when it's always true.

Example: If it rains, the sun doesn't shine.

First Conditional if + present ==> will + verb

We use it to make predictions or talk about actions or states that may or may not happen (likely 50/50)

Example: If it rains, I'll stay at home.

Second Conditional if + past simple ==> would + verb

Refers to actions or states that are not real or unlikely to be real in the future.

Example: If I won 1,000,000, I would travel.

Third Conditional if + past perfect ==> would have + past participle

Refers to actions in the past, and can be used to express regrets.

Example: If you hadn't given me a lift, I would have missed the train.

évidences

en permanence = présent

prédictions

dans le futur

imaginaire

dans le futur

regrets

avant, dans le passé

if + present

if + simple past

if + present perfect

present

will + base verbale

would + base verbale

would have + past part.

If clauses

There are three types of "if" clauses :

condition possible
condition in theory possible
condition not possible (too late)

type	"if" clauses	main clauses
condition possible	Simple Present	will + future
condition in theory possible	Simple Past	would + Infinitive (Conditional)
condition not possible	Past Perfect	would + have + past participle (Conditional Perfect)

type		example
condition possible	positive	If I learn, I' ll pass the exam.am.
condition possible	negative	If I learn, I won't fail the exam.
condition in theory possible	positive	If I learned, I would pass the exam.
condition in theory possible	negative	If I learned, I wouldn't fail the exam.
condition not possible	positive	If I had learned, I would have passed the exam.
condition not possible	negative	If I had learned, I wouldn't have failed the exam.

Conditional Types

The conditional sentence in English can be seen in terms of three principal types.

Type I

We use this type to imply that it is likely that the action in the if-clause will be performed. This kind is structured as follows:

If-clause	main clause
Verb in the present tense	Verb in the future tense
If you work hard,	you will succeed.

It is still probable that you will succeed if the condition (to work hard) is fulfilled.
N.B. The verb in the if-clause is never in the future.

Verb in the present tense	verb in the imperative
If you want to take a photo,	press this button.

Type II

This type however is used to indicate that the idea is improbable or unreal. The result of the condition is imaginary. It is structured as follows:

If-clause	main clause
Simple past tense (subjunctive)	conditional tense (would do etc.)
If she had wings,	she would fly.

N.B.: It is more a wish than anything probable to occur.

Type III

It is an impossible condition. The structure is as follows:

If-clause	main clause
Past perfect tense	perfect conditional
If + past perfect	should / would have done
If she had been tall enough,	she would have been recruited.

This implies that she was not tall enough that's why she wasn't recruited. It is impossible because the sentence refers to past events that had already finished.

Type Zero

Some scholars add a fourth basic kind which they refer to as "Zero conditional" or "Conditional type Zero", which I cannot recognize as such because its structure can in no way be considered conditional. The conditional, roughly speaking, means the uncertain whereas this type of conditional mostly deals with facts. The reasons if I have to name some are,

The result is always a fact. E.g. If you drop sugar into water, it melts.
It is used when there is no condition. And since there is no condition, what does it do here? E.g. If you don't water the plants, they die.
The "if" can simply be replaced by "when" or "whenever" in this form only.
Its structure is, [If + present simple, present simple] whereas, the conditional, in academic grammar, is put under modal verbs (will, would, should) have to be there.
It is used normally to describe facts or to explain how things work. E.g. If you pedal, the bike moves. As the answer is always true, therefore the conditional clause is no conditional at all.

In brief there is no condition in this type because it is not predictive. Compare these examples and see the difference:

If you throw a piece of wood in the sea, it floats. (This is true and it is experimented)

If you drop an egg down, it breaks. (This is true and it is experimented)

Here there is no condition because it is scientifically proven that wood never sinks no matter what the water is, potable or salty.

If you throw this chair in the sea, it will float. (it is probable only)

If you drop this egg down, it will break. (The egg will break on condition you drop it down)

The chair will float only on condition you throw it into the sea, but if you donďż˝t the whole conditional is concealed. So the if-clause is the basic of the prediction (the result).

In this case, there is a condition as we can predict the result of the condition. We have to take into consideration that it is probable that the wood in the chair could bear the iron and it is likely that the chair floats. Another thing is also to be taken into consideration, namely the density of salt in the water of the see. -----------------------------------------

Practice

Choose the right type for each sentence and click it:

1. If this wall fell down, many people would be hurt.	Type I	Type II	Type III
2. If wishes were horses, beggars would ride.	Type I	Type II	Type III
3. If you speak more slowly, everybody will understand you.	Type I	Type II	Type III
4. She would have got a prize if she had done a good job.	Type I	Type II	Type III
5. They will come if you invite them.	Type I	Type II	Type III
6. If I were a singer, I'd sing for peace in the world.	Type I	Type II	Type III
7. If I have time, I'll examine you.	Type I	Type II	Type III
8. If you had left earlier, you wouldn't have missed the train.	Type I	Type II	Type III
9. If the test had been easier, I'd have had a full mark.	Type I	Type II	Type III
10. You won't learn much if you don't work harder.	Type I	Type II	Type III

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Conditional sentences

The conditional sentences are sometimes confusing for learners of English.

Watch out:

1) Which type of the conditional sentences is used?

2) Where is the if-clause (e.g. at the beginning or at the end of the conditional sentence)?

There are three types of the if-clauses.

type	condition
I	condition possible to fulfill
II	condition in theory possible to fulfill
III	condition not possible to fulfill (too late)

Form

type	if clause	main clause
I	Simple Present	will-future (or Modal + infinitive)
II	Simple Past	would + infinitive *
III	Past Perfect	would + have + past participle *

Examples (if-clause at the beginning)

type	if clause	main clause
I	If I study,	I will pass the exam.
II	If I studied,	I would pass the exam.
III	If I had studied,	I would have passed the exam.

Examples (if-clause at the end)

type	main clause	if-clause
I	I will pass the exam	if I study.
II	I would pass the exam	if I studied.
III	I would have passed the exam	if I had studied.

Examples (affirmative and negative sentences)

type		Examples
		long forms	short/contracted forms
I	+	If I study, I will pass the exam.	If I study, I'll pass the exam.
I	-	If I study, I will not fail the exam. If I do not study, I will fail the exam.	If I study, I won't fail the exam. If I don't study, I'll fail the exam.
II	+	If I studied, I would pass the exam.	If I studied, I'd pass the exam.
II	-	If I studied, I would not fail the exam. If I did not study, I would fail the exam.	If I studied, I wouldn't fail the exam. If I didn't study, I'd fail the exam.
III	+	If I had studied, I would have passed the exam.	If I'd studied, I'd have passed the exam.
III	-	If I had studied, I would not have failed the exam. If I had not studied, I would have failed the exam.	If I'd studied, I wouldn't have failed the exam. If I hadn't studied, I'd have failed the exam.

* We can substitute could or might for would (should, may or must are sometimes possible, too).

I would pass the exam.

I could pass the exam.

I might pass the exam.

I may pass the exam.

I should pass the exam.

I must pass the exam.

- type I

Use

It is possible to fulfil a condition which is given in the if-clause.

Form

if clause	main clause
Simple Present	will-future or infinitive or Modal + infinitive

Examples

If I study,	I will pass the exams.
If you see John tonight,	tell him to e-mail me.
If Ben gets up early	he can catch the bus.

The if-clause can be at the beginning or at the end of the sentence.

If I study,	I will pass the exams.
I will pass the exams	if I study.

type 02

Use

It is theoretically possible to fulfil a condition which is given in the if-clause.

Form

if clause	main clause
Simple Past	would + infinitive or could + infinitive or might + infinitive

Examples

If I studied,	I would pass the exams.
If I studied,	I could pass the exams.
If I studied,	I might pass the exams.

The if-clause can be at the beginning or at the end of the sentence.

If I studied,	I would pass the exams.
I would pass the exams	if I studied.

type 03

Use

It is impossible to fulfil a condition which is given in the if-clause.

Form

if clause	main clause
Past Perfect	would + have + past participle or could + have + past participle or might + have + past participle

Examples

If I had studied,	I would have passed the exams.
If I had studied,	I could have passed the exams.
If I had studied,	I might have passed the exams.

The if-clause can be at the beginning or at the end of the sentence.

If I had studied,	I would have passed the exams.
I would have passed the exams	if I had studied.