Explanation and examples for a better understanding

1. Zero Conditional: certainty
We use the so-called zero conditional when the result of the condition is always true, like a scientific fact.
Take some ice. Put it in a saucepan. Heat the saucepan. What happens? The ice melts (it becomes water). You would be
surprised if it did not.
IF condition result
present simple present simple
If you heat ice it melts.
Notice that we are thinking about a result that is always true for this condition. The result of the condition is an absolute
certainty. We are not thinking about the future or the past, or even the present. We are thinking about a simple fact. We use the
present simple tense to talk about the condition. We also use the present simple tense to talk about the result. The important
thing about the zero conditional is that the condition always has the same result.
We can also use when instead of if, for example: When I get up late I miss my bus.
Look at some more examples in the tables below:
result IF condition
present simple present simple
I am late for work if I miss the 8 o'clock bus.
My boss gets angry if I am late for work.
People get hungry if they don't eat.
Does ice melt if you heat it?
IF condition result
present simple present simple
If I miss the 8 o'clock bus I am late for work.
If I am late for work my boss gets angry.
If people don't eat they get hungry.
If you heat ice does it melt?

3. First Conditional Sentences (Future possible)
First clause Second clause
If + Pp + present simple + Pp+ will /may/might + verb

If I do my homework now, I will go to the movies tonight.
First clause Second clause
If I do my homework now, I may go to the movies tonight. 
First clause Second clause
If I do my homework now, I might go to the movies tonight.
First clause Second clause
Vice versa
I will go to the movies tonight, If I do my homework now.
Second clause First clause
Negative
If I don’t do my homework now, I won’t go to the movies tonight.
First clause Second clause
If my parents aren’t at home tonight, I will go to the disco.
definite
It is possible, but
not definite

4. Choose the correct response for each of the sentences:
1. If you _________ greasy food, you will become fat.
eat
will eat
2. If your sister goes to Paris, she _________ a good time.
has
will have
3. If he _________ that, he will be sorry.
will do
does
4. If I leave now, I ________ in New York by 8:00 PM.
will arrive
arrive
5. You ________ on your test if you don't study.
won't do well
don't do well

5. 6. They won't know the truth if you ________ them.
won't tell
don't tell
7. If I bake a cake, ________ have some?
will you
do you
8. If he ________ you, will you answer the phone?
will call
calls
9. If you don't go to the party I ________ very upset.
am
will be
10. If you get a haircut you ________ much better.
will look
look

6. Second Conditional Sentences (present unreal)
First clause Second clause
If + Pp + past simple + Pp+ would + verb + complement
If I needed help, I would ask you.
First clause Second clause
If I needed help, I could ask you.
First clause Second clause
If I needed help, I might ask you.
First clause Second clause
In reverse
I would ask you, If I needed help.
Second clause First clause
Negative
If I didn’t need help, I wouldn’t ask you.
First clause Second clause
If I saw that film, I wouldn’t enjoy it.
First clause First clause

7. P.P verb
I If my friend were here, you could meet him.
YOU first clause second clause
HE If I were you, I would study
SHE first clause second clause
IT were Negative
WE If today were Saturday, I wouldn’t have to work.
YOU
If it wasn't raining, we would go to the beach.
THEY

8. 1. If my grandfather were younger, He _________ so many things.
wouldn't forget
didn't forget
2. If I _________ more money, I would buy a new car.
would have
had
3. If she had an umbrella, she _________ wet.
wouldn't get
didn't get
4. If we ________ a car, we would get there in 30 minutes.
would have
had
5. I ________ more careful if I were you.
would be
were
6. If animals could talk, I wonder what they ________?
said
would say
7. If she ________ harder, she would make more money.
will work
worked

9. 8. If he changed jobs, He ________ much happier.
will be
would be
9. If it wasn't raining, we ________ to the beach.
would go
will go
10. You wouldn't feel so tired if you ________ more.
will sleep
slept

10. 1. If his nose were smaller, he _________ very handsome.
a) would be b) was
2. I would come if I _________ a car.
a) would have b) had
3. If she _________, she would tell him.
a) knows b) knew
4. If his parents didn't give him money, he ________ so much.
a) wouldn't go out b) didn't go out
5. If she ________ me, she would have told me.
a) didn't believe b) wouldn't believe
6. He wouldn't say that if he ________ it.
a) wouldn't mean b) didn't mean
7. I ________ on a trip around the world if I won the lottery.
a) would go b) will go
8. I ________ that if I were you.
a) will not do b) would not do
9. If these walls _________ thicker, we wouldn't hear the neighbors.
a) would be b) were
10. If I were a millionaire, ________ a mansion.
a) I'd buy b) I'm going to buy

11. Third Conditional: no possibility
The first conditional and second conditionals talk about the future. With the third conditional we talk about the past. We talk about a condition in
the past that did not happen. That is why there is no possibility for this condition. The third conditional is also like a dream, but with no possibility
of the dream coming true.
Last week you bought a lottery ticket. But you did not win. :-(
condition result
Past Perfect WOULD HAVE + Past Participle
If I had won the lottery I would have bought a car.
Notice that we are thinking about an impossible past condition. You did not win the lottery. So the condition was not true, and that particular
condition can never be true because it is finished. We use the past perfect tense to talk about the impossible past condition. We use WOULD HAVE
+ past participle to talk about the impossible past result. The important thing about the third conditional is that both the condition and result are
impossible now.
Sometimes, we use should have, could have, might have instead of would have, for example: If you had bought a lottery ticket, you might have
won.
Look at some more examples in the tables below:
IF condition result
past perfect WOULD HAVE + past participle
If I had seen Mary I would have told her.
If Tara had been free yesterday I would have invited her.
If they had not passed their exam their teacher would have been sad.
If it had rained yesterday would you have stayed at home?
If it had rained yesterday what would you have done?

12. result IF condition
WOULD HAVE + past participle past perfect
I would have told Mary if I had seen her.
I would have invited Tara if she had been free yesterday.
Their teacher would have been sad if they had not passed their exam.
Would you have stayed at home if it had rained yesterday?
What would you have done if it had rained yesterday?

13. Third Conditionals
Put in the correct third conditional verb form:
1. If you ______________ (not / be) late, we ______________ (not / miss) the
bus.
2. If she ______________ (study), she ______________ (pass) the exam.
3. If we ______________ (arrive) earlier, we ______________ (see) John.
4. If they ______________ (go) to bed early, they ______________ (not / wake)
up late.
5. If he ______________ (become) a musician, he ______________ (record) a
CD.
6. If she ______________ (go) to art school, she ______________ (become) a
painter.
7. If I ______________ (be) born in a different country, I ______________
(learn) to speak a different language.
8. If she ______________ (go) to university, she ______________ (study)
French.
9. If we ______________ (not / go) to the party, we ______________ (not /
meet) them.
10. If he ______________ (take) the job, he ______________ (not / go) travelling.
11. He ______________ (be) happier if he ______________ (stay) at home.
12. She ______________ (pass) the exam if she ______________ (study) harder.

14. 13. We ______________ (not / get) married if we ______________ (not / go) to
the same university.
14. They ______________ (be) late if they ______________ (not / take) a taxi.
15. She ______________ (not / meet) him if she ______________ (not / come) to
London.
16. He ______________ (take) a taxi if he ______________ (have) enough
money.
17. I ______________ (call) you if I ______________ (not / forget) my phone.
18. We ______________ (come) if we ______________ (be) invited.
19. She ______________ (not / do) it if she ______________ (know) you were ill.
20. He ______________ (be) on time if he ______________ (leave) earlier.