This document summarizes the different types of conditionals in English:
Type 0 conditionals refer to general truths and use the present tense. Type 1 conditionals refer to possible future events and use the present or future tenses. Type 2 conditionals refer to unlikely or imaginary situations and use the past tense and modal verbs. Type 3 conditionals refer to unlikely past events and use the past perfect and modal verbs. There are also mixed conditionals that refer to past events affecting the present. Other conditional expressions include unless, as long as, provided/providing, or, otherwise, and supposing.
2. Type 0
Uses;
We use the zero conditional when we want to talk about facts or things that are
generally true. Scientific facts are often covered by the zero conditional: "When
you heat ice, it melts."
uses if or when, must be followed by the simple present or imperative.
For example:
"When it rains, tennis lessons are held in the gym."
"If it rains, tennis lessons are held in the gym."
3. Structure
Affirmative: If + subject + present tense + action
If you heat ice, it melts.
Ice melts if you heat it.
If I go to bed late, I wake up late.
You pay higher income taxes when you earn more money.
Negative: (IF/WHEN) + Present Simple + Not + Present Simple
If you exercise, you do not gain weight.
If I don’t study, I don’t do well on tests.
If you are not on time, you lose one mark.
Question: Auxiliary ( do- does) + Subject + Verb + If/When + subject + Present simple + ?
Does ice melt if you heat it?
When do you wake up if you have to work?
If you have to work, when do you wake up?
5. Type 1
Uses;
The type 1 conditional refers to a possible condition and its probable result. We don't know
for sure whether the condition actually will be fulfilled or not, but the conditions seems rather
realistic. We often use such sentences to give warnings.
Structure;
If Clause Main Clause
If + Subject + Simple present + action, Subject + Future Simple
Questions;
WH word + auxiliary + subject + verb in infinitive + if + subject + simple present + rest of the sentence?
Examples;
If it rains, you will get wet.
If Sally is late again I will be mad.
If you don't hurry, you will miss the bus.
What will Harry do if it rains?
6. Type 2
Structure: If clause Main clause
Subject + would + verb in infinitive
If + subject + verb in past simple + action Subject + wouldn't + verb in infinitive
Wh + would + subject +verb in infinitive + ...
- If I won the lottery, I would travel to London.
- If I won the lottery I wouldn't travel to London
- If you won the lottery, where would you travel to?
Uses and examples:
1- We use conditionals type 2 to express events in the future that are probably not going to be true.
For example;
- If I won the lottery, I would buy a big house.(most probably I won't win the lottery)
2- We also use it to talk about something in the present which is impossible, because it's not true.
For example;
- If I had his number, I would call him
- If I were you, I wouldn't go out with her.
7. Type 3
Uses;
● to express conditions in the past that did not happen. Often used to express
criticism or regret with would have, could have or should have.
Structure;
If + past. perfect + would have + past participle
Examples;
● If she had studied, she would have passed the exam (but she did not study so
she did not pass it)
● If I hadn't eaten so much, I wouldn't have felt sick (but I did eat a lot, and so I
did feel sick).
8. Mix conditional
This type of mixed conditional refers to an unreal past condition and its probable
result in the present. It express a past situation that affects the present one
Structure;
● If + past perfect… would / could + simple form
● If + past perfect… would / could + be +ing
Examples;
● If he had eaten more at lunchtime, he wouldn't be hungry now.
● If he had got a better job, he would be living in a nice and big house.
9. Other expressions
Unless: Unless I phone you, you can assume the train’s on time. (If I do not
phone you, you can assume the train is on time.)
As long as: You can play in the living room as long as you don’t make a mess.
Provided/providing: They may do whatever they like provided that it is within the
law.
Or; You’ve got to start studying, or you’ll fail all those exams. (If you don’t start
studying, you will fail the exams.)
Otherwise: We should better send it now, otherwise it’ll take days. (If we do not
send it now, it will take days.)
Supposing: Supposing I don’t arrive till after midnight, will the guest-house still be
open?(Imagine if I don’t arrive till after midnight …)
When: When you heat ice, it melts (If you heat ice, it melts)