Here are the conditional sentences with the verbs filled in: - If Mary had come to the party, Tom would have been happy. - If she didn't like soup, she would eat a sandwich. - If you freeze water, it turns to ice. - If I lost my pet, I would be upset. - If you don't want it, I'll have that last piece. - If water boils, it produces steam. - If I had a car, I wouldn't take the bus. - Dan wouldn't have missed the bus if he had left on time. - My parents will be angry if Tina doesn't clean her room.

1. Conditional Clause

2. Conditional Sentences
There are four types of conditional sentences. It
is sometimes called the “if clause”. It is formed by
two clauses.
Conditional Sentences

3. Conditional Sentences
If If clause
main clause
Conditional Sentence = If clause, main clause.
= Main clause, if clause.
4
- Conditional type 0
- Conditional type 1
- Conditional type 2
- Conditional type 3

4. (Conditional Type zero)
(always true, laws of
nature)
- If you heat the water, it boils.
If clause Main clause
- If you mix blue and yellow, you get green.
If clause Main clause

5. (Conditional Type zero)
Conditional Sentences
If + present simple, subject + v1
Example
If you throw salt on the snow, the snow melts.
If you lie in the sun too long, your skin turns red.
If a policeman sees an accident, he asks for a driving
license.

6. Present Condition (Type one)
(possible actions in the future)
- If he comes, I will go.
If clause Main clause
- We will stay home if it
rains. Main clause If clause

7. Conditional Sentences
will
If + present simple, subject + shall + base form
can
may
Example
- If she reads the books, she may pass the exam.
If you wake up before me, give me a call.
If he comes, tell him to meet me.

8. 1. If he talks (talk) in class, the teacher will punish him.
2. If I use (use) her bicycle, my sister will be angry.
3. If he is alone, I will tell (tell) him everything.
4. I’ll like Mike if he isn’t (not be) selfish.
5. If these is no bus, we won’t go (not go) to Chiang Mai.
6. Golf will sleep better if he doesn’t drink (not drink) so
much beer.
7. If the weather forecast is (be) correct, it may rain
tomorrow.

9. Present Conditional Unreal (Type two)
Present Conditional Unreal
- If I won the lottery, I would retire.
- If Yaya finished her homework, she might hang out.
Conditional sentences
would
If + past simple + subject + might + base form
should
could

10. Present Conditional Unreal (Type two)
Example
- If I had the time, I would take up a sport.
- If Sarah met the famous person, she might ask for a photo.
*
If-clause verb verb
to be were
If I were a guard, I should stand on duty all day
long.
If she were a millionaire, she would take a trip
everywhere.

11. 1. If I knew her well, I would speak (speak) to her.
2. I might hurry up (hurry up) if I were you.
3. She will be irritable if she didn’t get (not get) enough sleep.
4. If she worked (work) harder, she would get a better salary.
5. You were (be) an angle if you helped me raise the fund.
6. If you didn’t talk (not talk) so much, you would work better.
7. I wouldn’t know (not know) what to do if you went away.

12. Past Conditional Unreal (Type three)
Past Conditional Unreal
(Impossible actions in
the past)
- If I had studied hard, I would have passed the exam.
(I didn’t study hard.) (I didn’t pass the exam.)
- If you had gone to the party, you would see him.
(You didn’t go to the party.) (You didn’t see him.)
- She could have studied Thai if she had taken a course.
(She didn’t study Thai.) (She didn’t take a course.)

13. Past Conditional Unreal (type three)
Conditional sentences
would
If + past perfect + subject + might + have + v3
(had + v3) should
could
Example
- If I hadn’t been ill, I should have gone to the party.
- (I was ill) (I didn’t go to the party.)
- If she hadn’t fallen, she wouldn’t have hurt her ankle.
- (She fell) (She hurt her ankle.)

14. If he hadn’t wasted (not waste) his money on gambling, he could have
bought a house.
If they had arrived on time, I would have been (be) surprise.
He would have been (be) very angry if he had known the truth.
If the weather had been (be) nice, we would have gone to the beach.
If I had received (receive) your message, I would have come at once.
If you had come yesterday, you would have met (meet) Justin Bieber.
I would have looked you up if I had known (know) you were living in Bangkok.
If they had invited us naturally, we would have gone (go) to the party.

15. Unless = if not
• We use unless instead of if …. not in a
conditional clause. The verb after unless is
always in the affirmatives but the meaning is
negative.
- Unless he gets here soon, we’ll have to start
the meeting without him.
- If he doesn’t get here soon, we’ll have to
start the meeting without him.

16. If clause Main clause
Type 0 Present simple Present simple
General Truth (s. + V1) (V1)
Type 1 Present simple Future
Possible actions (s. + V1) (will + base form)
in the future
Type 2 Past simple Past future sim
Unreal actions in (s. + v2) would+ base form
the present
Type 3 Past Perfect Past future perfect
Impossible (s. + had + v3) would+ have+ v3
action in past

17. • If Mary had come to the party, Tom _________ (be)
happy.
• If she _________ (not like) soup, she would eat a
sandwich.
• If you freeze water, it turns_________ (turn) into ice.
• If I _________ (lose) my pet, I would be upset.
• If you don’t want it, I __________ (have) that last piece.
• If water _________ (boil), it produces steam.
• If I __________ (have) a car, I wouldn’t take the bus.
• Dan wouldn’t have missed the bus if he _______ (leave)
on time.
• My parents will be angry if Tina ________ (not/ clean)
her room.