Write the verbs in brackets in the correct form.
There are several types of conditional sentences. The first one indicates that something is possible, probable or real: if (present), (will + infinitive)
or (will + infinitive) if (present)
If we have time, we will pay you a visit.
If you (buy) me a beer, I (help) you with your homework.
If he (be) punctual, we (catch) the 10.45 train.
If it has stopped raining, I (show) you round town.
You (arrive) late if you (not hurry) up.
If it (continue) to snow, we (not be) able to go there today.
There are other options to the ones seen in the previous section:
If you want a kiss, come here.
(if (present), (imperative)
Don't do it if you're not sure.
((imperative) if (present)
Metals expand if they're heated.
(a universal fact→if (present), (present)
If (=whenever) she comes in, he (always) goes out.
(a habit→if (present), (present)
You can stay here if you like.
(You can use other modal verbs instead of will
Metals (contract) if they (be) cooled.
(not stand) up if you (be) tired.
If I (go) home late, my parents often (get) angry.
(sit) down if you (want) to take another tea.
If it (be) hot, we usually (spend) the day on the beach.
As for the second type, it indicates that something is improbable or unreal: if (past), (would + infinitive)
or (would + infinitive) if (past)
If I were you, I would tell the truth.
If she were here, she would know what to do.
I'd buy a big house if I won the lottery.
If it (not be) raining cats and dogs, I (go) with you.
What you (do) if you (see) a burglar at home?
If he (has) the answer, he (not share) it.
If Lionel (get) to know this, he (ruin) your marriage.
You (have) to obey me if your dad (be) here.
The third type refers to the past, and the past cannot be changed, which is why these sentences are called "impossible conditionals": if (past perfect), (would have + past participle)
or (would have + past participle) if (past perfect)
If she had been here, we would have won the match.
They could have helped us if they hadn't had the accident.
If you (love) them, you (not abandon) them.
If Mary (be) in, she (answer) the phone.
They (not run) out of petrol if they (fill) their car in.
If he (express) his feelings, he (not lose) her.
If I (not have) an important meeting, I (take) you out to dinner last night, but I couldn't skip that meeting.
5. We can link the present or future to the past by combining the second and third types, as in the following examples:
If you had drunk that, you would be dead now.
If my son were ill, I would have noticed.
a I (be) rich now if I (marry) him then.
b I (take) the dog out to do his business tomorrow morning if you (lend) me a hand this morning.
c If they (need) your help now, they (say) something about it before they left.
d If you (not tell) anybody as I told you, we (not be) in such an embarrassing situation now.
e If he (not study), he (not be) the chairman of this company now.
6. Complete the following conditional sentences:
a If there is another strike, we...
b If it weren't sprinkling with rain, we...
c He wouldn't be so unhappy if...
d They would have come if...
e If I were you, I...
f If it hadn't been for you, I...
g I could have helped you if...
h She may forget about it if...
i Your marks are very poor. You'll have to repeat the year unless...
j I'll lend him my car provided that...
k Nobody will know our secret so long as you...
l If you play truant again, you...
m If he hadn't been driving so fast, he...
n If they fired me, I...
o If he hadn't caught me red-handed,...
p If I hadn't entered that disco then,...
q If it continues without raining, our crops...
r They'd give you a bonus if...
s If it weren't for her, they...
t We would have arrived at the meeting in good time if...
u My parents often get cross with me if I...
v Don't let the cat out of the bag again if you...
w He may find out the truth if...
x Life would have been much harder for him if...
y If you need more money,...
z If you say that again,...
7. Rewrite each of the following sentences without changing its meaning. Use IF.
I'm tired, so I won't dance.
If I weren't tired, I'd dance.
a It's spitting with rain, so I won't go out.
b Tell me what happened or I'll get angry.
c The reason why she was so sad was that her husband had abandoned her.
d Either you keep your mouth shut, or you'll get into trouble.
e She couldn't attend the reception because she was ill in bed.
f I think you should drink less.
g He made a lot of mistakes in his composition, so he failed.
h He lives abroad, so we seldom see each other.
i Visit us some time next week, and we'll take you sightseeing.
j Put this record on and I'll dance with you.
k I can't go there with you because I have a lot of things to do.
l Your stomach aches so terribly because you didn't follow my advice last night.
m We didn't buy the flat, as it was extremely expensive.
n Keep calm. It'll do you good.
o He's so lonely because he's very selfish.
p They used low-quality materials to build the house, so they will have to pull it down now.
q In my opinion, you should sell the house at a cheaper price.
r The neighbours' dog kept on barking the whole night, so I didn't sleep a wink.
s I don't want to go for a swim because it's rather chilly outside.
t I didn't go to school today because I have an awful headache.
u I'm afraid of spiders, so I was very frightened.
v I didn't say hello to you because I didn't see you.
w I don't travel very often. I'm very poor.
x He robbed a bank, so he was arrested.
y I conquered her heart thanks to you.
z I was infatuated with her, which is why I covered up for her.
We do not write a comma if we place the conditional clause after the main one, but it is usually added if we put the conditional clause first:
If we begin now, we will finish before dark.
We will finish before dark if we begin now.
Instead of if
, we may use other conditional conjunctions:
If she doesn't help me, I won't be able to go.
Unless she helps me, I won't be able to go.
I'll go if he shuts up.
I'll go provided (that) / providing (that) / as long as / so long as he shuts up.
In questions, only the main clause takes the interrogative form:
Will he come if it rains?
If it rains, will he come?
contracts to 'll
and will not
, to won't
Imperatives are orders, requests, and so on. Note that the subject is not mentioned.
is also possible, but less usual: Metals will expand if they are heated
Notice that were
is preferred to was
here, at least in a more formal style.
contracts to 'd
. Other modal verbs in their conditional (or past) forms (such as could
) are also possible, but with nuances of meaning.
See unit 7, sections 11 and 12
for further information about the past perfect.
See footnote 6