Conditional sentences contain two clauses: a condition clause (if-clause) and a result clause. There are four types of conditional sentences: zero conditional for facts, first conditional for probable future events, second conditional for unlikely events, and third conditional for hypothetical past events. Mixed conditionals combine elements of different conditionals. Alternative constructions include "unless", "otherwise", and "wish/if only".

1. CONDITIONAL SENTENCES
Zero
First
Second
Third

2. Use of conditional sentences
 Conditional sentences allow us to talk about
POSSIBLE and IMPOSSIBLE/ UNREAL
SITUATIONS and their CONSEQUENCES.
 So, conditional sentences typically contain
TWO CLAUSES:
- a condition clause (if-clause)
- a result clause

3. ZERO CONDITIONAL
if+ present simple, / present simple
Present simple / if+present simple
 To describe A STRAIGHTFORWARD
CAUSE AND EFFECT
If you press that button, the engine starts
 To write a SCIENTIFIC TRUTH
If you mix oil and water, the oil floats

4. FIRST CONDITIONAL:
IF + PRESENT SIMPLE , WILL
WILL / IF+PRESENT SIMPLE
 When we believe that something is LIKELY
(PROBABLE) TO HAPPEN:
If I have the money, I will buy a new car
You will pass your exams if you study hard
 For PROMISES or THREATS:
If I go to America, I’ll send you a postcard
If you don’t do your homework, you won’t go out

5. POSSIBLE VARIATIONS OF THE MAIN
FORM:
1) Instead of WILL, we may have other MODAL VERBS
If you keep on behaving like that, you may/might have
problems.
If you finish your work in time, you can/may go home.
If you want to lose weight, you must/should eat less bread.
If you see Tom, could you ask him to ring me?.
2) Instead of WILL, we may have an IMPERATIVE
If you are hungry, make yourself a sandwich.

6. SECOND CONDITIONAL:
IF+ SIMPLE PAST, WOULD/COULD/ MIGHT +
INFINITIVE
 when we think that a situation is NOT VERY
LIKELY TO HAPPEN
If the students were more serious, they could have
better results
 for UNREAL or IMAGINARY SITUATIONS:
If I were the President of the USA, I would help poor
people all over the world
 for ADVICE:
If I were you, I would think about it
for POLITE REQUESTS:
Would you mind if I borrowed these CDs?

7. EXAMPLE OF POSSIBLE VARIATIONS
 If you tried again, you might succeed.
 If I knew her number, I could ring her up.
 If I were on holiday, I might be touring Italy.

8. THIRD CONDITIONAL
IF+PAST PERFECT , WOULD/COULD/MIGHT HAVE
+PAST PARTICIPLE
 To describe IMAGINARY or UNREAL
SITUATIONS in the past
If I had won the lottery, I wouldn’t have had financial
problems.
(= but I didn’t win the lottery and so I had financial
problems)
 To express REGRETS:
If you had bought me a diamond ring, I would have
loved you forever.
(= but you didn’t buy me one, so I stopped loving you!)

9. Examples of possible variations:
- If I had know you were coming, I could have
met you at the airport.
(I didn’t know you were coming, so I didn’t meet
you there)
- We might have passed if we had studied
harder.
(We didn’t study hard, so we didn’t pass)

10. ALTERNATIVES TO ‘IF’...
 UNLESS (= if not)
You won’t lose weight, unless you stop eating chocolate.
Unless you hurry you’ll miss the train.
 OTHERWISE (= if it doesn’t happen/ if it didn’t
happen/ it it hadn’t happen)
Stop eating chocolate, otherwise you won’t lose weight.
Her father pays her fees, otherwise she wouldn’t be
here.
He studied very hard, otherwise he wouldn’t have had
such good marks.

11. ALTERNATIVES TO ‘IF’...
 ASLONG AS / PROVIDED (THAT) / ON
CONDITION THAT....
I’ll lend you my books as long as / provided that / on
condition that you promise to bring them back.
 INVERSIONS
Had I known that he was upset, I wouldn’t have said
anything.
 EVEN IF...
Even if I were a millionaire, I wouldn’t give him
any money.

12. MIXED CONDITIONALS
It combines the THIRD CONDITIONAL (in the
condition clause) with the SECOND
CONDITIONAL (in the result clause):
If I hadn’t eaten that seafood, I wouldn’t feel so
awful now.
If the weather had been fine last week, there
would be roses in the garden now.

13. MIXED CONDITIONALS
 Or the SECOND CONDITIONAL (in the if-
clause) with the THIRD CONDITIONAL (in
the main clause)
If he weren’t so shy, he would have asked her
to marry him.
If Emma weren’t so lazy, she would have
studied harder.
* It happens when the time reference in the if-
clause is different from the main clause.

14. I wish / If only
We use I wish/ If only + past simple to talk
about a desire for the present.
I’m not very tall. I wish/If only I were taller.
I haven’t got a house at the beach. I wish/ If
only I had a house at the beach.

15. I wish / If only
We use I wish/If only + past participle to talk
about a regret about something in the past.
I didn’t study very hard. I wish/ If only I had
studied harder.
I ate a lot; I’m so full. I wish/ If only I hadn’t
eaten so much.

16. I wish / If only
 We use I wish/If only + would-inf to complain
about something annoying.
My parents never let me stay at my friends’
houses. I wish/ If only my parents would let
me stay at my friends’ houses.
He is always talking while the teacher is
explaining. I wish/ If only he would stop
talking.