If I see Andrew at the meeting, I'll give him your message. There are three main types of conditional sentences: first, second, and third conditional. The tenses used can vary in the if and main clauses for each type. Mixed conditionals using different types together are also possible if they make sense contextually. Implied and real conditionals express conditions without using "if".

1. CONDITIONAL
SENTENCES

2. 3 MAIN TYPES:
First, second and third
conditional

3. First Conditional
If I see Andrew at the meeting, I'll give him your message.
PRESENT SIMPLE FUTURE SIMPLE
USE: To talk about something that is quite likely
to happen in the future. It is very possible that I
will see Andrew at the meeting, in which case I'll
give him your message. The condition is quite
likely to be fulfilled. For presenting future plans,
real possibilities, steps in an argument, points in a
procedure, predictable consequences,
instructions.

4. Second Conditional (Hypothetical)
If my parents were alive, they would be very proud of me now.
PAST SIMPLE WOULD + INFINITIVE
USE: To talk about a present situation which is impossible, a hypothetical
situation. The situation cannot be fulfilled because my parents are not
alive.
If she changed her job, she'd be much happier.
USE: To talk about a future event which is unlikely to happen. The
speaker doesn`t expect her to change her job. That is, it is unlikely that
the condition will be fulfilled.
What would happen if…?

5. Third Conditional
If she had worked harder, she would have passed her exams.
PAST PERFECT WOULD + PERFECT INFINITIVE
USE: To talk about something that might have happened
in the past, but didn`t. She didn`t work hard enough and,
consequently, she didn`t pass her exams.
It also expresses excuses, regrets and blame for past
events.
What would have happened if…?

6. The zero conditional
(factual)
What happens if…?
If I stay out late, I always take a taxi home.
PRESENT SIMPLE PRESENT SIMPLE
USE: To describe something that is generally true. The use of if here
is very similar to when. For presenting habits, general truths, rules,
typical patterns, correlations.
We can also use the past simple in the two clauses.
If I stayed out late, I always got a taxi home.

7. Conditional Sentences:
Variations in tenses
First Conditional: The if clause is usually in the present
simple. However, we can also use:
 Present continuous:
If he's still waiting for you, he'll be very angry.
 Present perfect simple:
If Rob's received your letter, he'll phone you.
 Present perfect continuous:
If it's been raining all night, you'll have to wear boots.
 Can: If I can finish work early, I'll help you.
 Should: If I should see him, I'll tell him the news.

8. The main clause usually has the verb will / shall.
But we can also use:
 Going to:
If Helen passes her exams, I'm going to buy her a present.
 Future continuous:
If we book this holiday, we'll be lying on the beach in two weeks` time.
 Future perfect:
If they win the next match, they'll have won every match in the season.
 Imperative:
If you need me, call me.
 Can / could, may / might, should / ought to,
must
If you don't eat your dinner, you can't have an ice cream.

9. Tense variations in conditional 2
The if clause usually takes the past simple. However, it
is also possible to use:
 Past continuous:
If you were coming with me, I`d give you a lift.
 Could
If I could have the day off, I`d go with you.
Were / was to:
If you were to ask Steve, I`m sure he would do it.

10. The main clause usually has the modal would
+ infinitive. However, the modals could and
might are also used and the infinitive can
be in the continuous form:
 If we had more money, we wouldn`t be living
here.
 If we had more money, we could go out more.
 If you asked Tony, he might do it for you.

11. Tense variations in conditional 3
The if clause is usually in the past perfect simple.
However, we can also use the past perfect
continuous or could + perfect infinitive.
If he had been travelling in the car, he would have
been killed too.
If we could have got a taxi, we would have come
round to see you.

12. The main clause usually has the modal would
+ perfect infinitive. However, we can also
use the modals could and might + perfect
infinitive.
If I had known there was no more work to do,
I could have stayed in bed.
If the ambulance had come sooner, he might
have been saved.

13. MIXED CONDITIONALS
 If-clauses can be mixed provided that they make sense within a context.
If-clause Main clause
Type 3 If she had worked harder
at university,
She would have a degree
now.
Type 2
(she didn`t work hard at
university
so she doesn`t have a
degree now. )
Type 2 If I were faster, I would have won the
race.
Type 3
(I´m not fast so I didn´t win the race.)
Type2 If they were studying all
morning,
they will be tired now. Type 1
(they were studying so they are tired now.)

14. Words other than if
Unless I won`t go out unless he comes too.
Even if Even if it rains, we`ll go to the match.
If only If only I had money, I would go out more.
As/so long as You can use the car as long as you take care of
it.
On condition
(that)
I`ll lend you the car on condition that you take
care of it.
Provided /
providing
(that)
I`ll lend you the car provided that you take care
of it.
Assuming
(that)
Assuming that you take care of the car, I`ll lend
it to you.

15. Suppose /
supposing (that)
Suppose you had a lot of
money, would you give up
work?
What if What if you had a lot of money,
would you give up work?
Imagine Imagine you had a lot of
money, would you give up
work?
In questions….

16. IMPLIED CONDITIONALS
Conditions are not always expressed in the form of
conditional clauses, particularly in spoken English.
They can be expressed in another way or they
may be evident from the context. The rules for the
verb usage are still followed in the result clause
(main clause).
He committed the crime, otherwise he wouldn’t have been
arrested. (implied conditional)
If he hadn’t committed the crime, he wouldn’t have been arrested.
I would have stayed longer, but he didn’t ask me to.
(implied conditional)
I would have stayed longer if he had asked me to.

17. Inversion
 If the first verb in a conditional if clause is
should, were or had, we can leave out if and
put the verb at the start of the clause. We do
this particularly in formal or literary English.
 Should any of this cost you anything, send me the
bill (If any of this should…)
 It would be embarrassing were she to find out the
truth. (… if she were to find out…)
 Had they not rushed to hospital, Dan would have
died. (If they hadn`t rushed…)

18. We use if it was / were not for + noun to say
that one situation is dependent on another
situation.
 If it wasn`t / weren`t for the fireman, my dog would
have died in the fire.
 If it hadn`t been for my parents, I wouldn`t have gone to
university.
We also use but for + noun with a similar
meaning:
 But for Jim`s support, I wouldn`t have got the
job.

19.  In real conditional sentence, we use
If… happen to,
If … should,
If … should happen to
to talk about something that may be possible
but is not very likely:
 If you happen to be in our area, drop in and see
us.
 If you should be in our area, …
 If you should happen to be in our area, …

20. Polite requests
We can use if… will in requests:
o If you will take your seats, ladies and gentlemen,
we can begin the meeting.
 if you want to make a request more polite,
you can use if…would:
o If you would take your seats, …

21. Now let's sing
some conditionals!