Conditionals are also known as if clauses and they are used to describe the result of an action that might happen in the present or future, or an action that might have happened but it didn’t in the past. There are four kinds of conditionals in English language: the zero conditional, the first conditional, the second conditional, and the third conditional.
In a zero conditional sentence the verb in both clauses is in simple present. The structure of a zero conditional statement is “if + simple present”, “simple present”.
“If” clause can come first or second.
You can replace “if” with “when”.
Use the zero conditional to make statement about the real world, general truths, facts that are proven and always true etc. It is also used to give instructions.
Ice melts if you heat it.
When you heat ice, it melts.
Ice melts when you heat it.
If your mom calls, tell her to meet me at 4 o’clock.
The structure of a first conditional statement is “if + present”, “will + base form”.
Use the first conditional to talk about a possible future situation and it’s consequences.
“If + present” is a clause and can come first or second.
If I miss the train, I will go by bus. (“If” means a possible future, maybe, it is a possibility ... “I will” shows what you will do if “if” happened)
She will not like if you go abroad. (“If” clause comes in the second part of the sentence and “will + base form” comes first)
The structure of a second conditional statement is “if + past”, “would + base form”.
Use the second conditional to talk about improbable/impossible/hypothetical future situations.
Don’t forget that would/wouldn’t is the same for all persons.
With can, use could + base form.
If I won a million dollars at the lottery, I would move back to Europe.
If I didn’t have Vietnamese wife, I wouldn’t live in Vietnam.
Would you work as a teacher if the school offered higher salary?
If I had a marriage certificate, I could get the Vietnamese visa.
Additional notes regarding the second conditional:
The contraction of would is “-‘d” and the contraction of would not is "wouldn’t".
The “if” clause can come first or second.
A very common expression used for giving suggestions is “If I were you”. (Example: If I were you, I would study one more foreign language.)
|First conditional||Second Conditional|
|Use the first conditional for possible future situations||Use the second conditional for improbable/impossible/hypothetical future situations|
|If I have time tomorrow, I will go with you to the zoo. (maybe I will have time)||If I had time tomorrow, I would go with you to the zoo. (I will not have time tomorrow, for sure)|
The structure of a third conditional statement is “if + past perfect”, “would have + past participle”.
Use the third conditional to talk about a situation in the past (situation which didn’t happen, an imaginary situation) and its consequences.
Let’s compare the following two sentences:
Yesterday I got up late and missed the bus. (This is the real situation, it happened yesterday)
If I hadn’t gotten up late yesterday, I wouldn’t have missed the bus. (This is an imaginary situation, it didn’t happen)
If I had known about the meeting, I would have gone.
If I hadn’t gone to that party, I wouldn’t have met my wife.
You wouldn’t have been late if you had gotten up earlier.
We wouldn’t have arrived at 6 o’clock if we hadn’t gotten lost.