What is a conditional sentence?
A conditional sentence is a sentence structure commonly used in English when we want to talk about something (a result) that may happen ONLY IF something else happens first (a condition). The condition may be something real or unreal / hypothetical, and the result could a definite result, or just a possible / likely result.
The most common type of conditional sentence uses if. These are the easiest conditional sentences to form and understand. You could also use unless, when, after, before or as soon as. Here, we will focus on using conditional sentences with if.
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There are 2 parts to a conditional sentence. These two parts are also called clauses. [A clause is any part of a sentence with a subject and a verb.]
Part 1 – the if or condition clause: the event that needs to occur; also called the dependent clause because it is not a complete sentence and is dependent on the 2nd part of the sentence.
Part 2 – the result or main clause, or what happens when the event in the if/condition clause occurs; also called the independent clause.
Either part can come first:
Changing the order of the clauses does not change the meaning; the two sentences above mean exactly the same thing.
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There are 4 types of conditional sentences in English:
0 (zero) conditional – real / factual conditional
If I eat too much, I get sick.
1st (first) conditional – future possible/real conditional
If I eat too much, I will get fat.
2nd (second) conditional – present unreal/hypothetical conditional
If I were fat, I wouldn’t be able to dance very well.
3rd (third) conditional – past unreal conditional
If I hadn’t eaten so much, I wouldn’t be so fat.




Melanie is a TESL-certified English teacher. She lives near Toronto, Canada. Through her blog, videos, podcasts, and social media, she helps thousands of people around the world improve their English. She makes English a little less confusing and a little more fun! She also helps people understand Canadian and American culture. She believes that natural interaction with a native speaker helps people practice what they have learned and builds their confidence with English!
{ 3 comments… read them below or add one }
Hello Melanie. I liked much this lesson. I understood most reading, because your written english is easy to read.
I have a doubt on last conditional. can I say?:
If I hadn't eaten so much, I wouldn't have been so fat. Is this right? Thanks.! Greetings.!
Hello Regulo,
I'm happy to hear you liked this lesson!
I have heard a lot of Brazilians say "I have a doubt." This is not an English expression! In English you can say "I have a question." In your case, you can say "I have a question about the last conditional."
Your sentence is correct:
"If I hadn't eaten so much, I wouldn't have been so fat."
Also,
"If I hadn't eaten so much, I wouldn't have gotten so fat."
I hope this helps!
Melanie
= )
Ah ok.! Thank you for correct me.!