ESCOLA SECUNDRIA DE HENRIQUES NOGUEIRA

CONDITIONAL SENTENCES: RULES & PRINTABLE WORKSHEET

Grammar: 'unless' and 'if'

Unless = if not.

This is a good example of a 'rule of thumb' one that is easy to remember and apply, but which is only a part of the whole story. Better to think of unless as meaning except if; except under these circumstances. So:

Ill be at your place at 9.00, unless [= except if] the bus is late.

The front room was never used, unless [= except if] we had important visitors.

In the first sentence there is only one reason why I might be prevented from being at

your place at 9.00, and that would be the bus being late. This is what Swan means when

he said A will happen if its not stopped by B. Likewise, in the second sentence there was only one circumstance when the front room was used: when we had important

visitors.

But unless is unlikely here:

Ill be angry if the bus isnt on time.

In this sentence the bus not being on time is the reason for my being angry. That is what

Swan means when he says A will result from something not happening.

The following sentence:

Ill be angry unless [= except if] the bus is on time.

That means: the only thing that will prevent me from being angry is the bus being on

time which sounds strange to say the least. Here are some more examples like that,

where unless isnt possible:

1. If you dont like it, you can leave. 2. If she wasnt so bossy, shed be quite nice. 3. If I didnt know a word, Id look it up.

UNLESS

Unless means the same as if...not. Like if, it is followed by a present tense, a past tense

or a past perfect (never by 'would'). It is used instead of if + not in conditional sentences

of all types:

Type 1: (Unless + present simple)

a. You'll be sick unless you stop eating. (= You will be sick if you don't

stop eating)

b. I won't pay unless you provide the goods immediately. (= If you don't

provide them I won't pay)

c. You'll never understand English unless you study this grammar

carefully. (= You'll never understand if you don't study...)

Type 2: (Unless + past simple)

a. Unless he was very ill, he would be at work.

b. I wouldn't eat that food unless I was really hungry.

c. She would be here by now unless she was stuck in the traffic.

Type 3: (Unless + past perfect)

a. The lady would never have seen the little mouse unless she'd had

perfect eyesight. (meaning, she actually saw it)

b. I wouldn't have phoned him unless you'd suggested it.

c. They would have shot her unless she'd given them the money.

Now, its time to start practicing. Simply, download this exercise and hand it back to your teacher.

Name: _______________________________________________________ Number: ______

If or Unless?

Choose the correct word.

Q1 - ___ you are caught drinking and driving, you will lose your license.

If

Unless

Q2 - ____ you stop smoking, you'll be seriously ill.

If

Unless

Q3 - I won't be able to do it ____ you help me.

if

unless

Either could be used here.

Q4 - ____ you stop making that noise, I'll call the police.

If

Unless

Either could be used here.

Q5 - ____ you're late, I'll leave without you.

If

Unless

Either could be used here.

Q6 - ___ he gets caught, he'll make a fortune.

If

Unless

Q7 - ____ he gets caught, he'll go to jail.

If

Unless

Q8 - I won't do it ____ you agree to help me; I'm not doing it alone.

if

unless

Q9 - ___ she pays up, we're going to be in real trouble.

If

Unless

Q10 - ____ we get the cheque today, we must bank it.

If

Unless

Q11 - She'll never agree to that ____ you accept her suggestions.

if

unless

Q12 - ____ they're late again, I'll be furious.

If

Unless

Q13 - I don't want to go out ____ it's raining- I hate getting wet.

if

unless

Q14 - We'll be in trouble ____ it goes wrong.

if

unless

Antnio Andrade