• The zero conditional is a structure
used for talking about general truths
-- things which always happen under
certain conditions. Following I will
explain how the zero conditional is
formed, and when to use it.
The structure of a zero
• A zero conditional sentence consists of
two clauses, an "if" clause and a main
clause (note that most zero conditional
sentences will mean the same thing if
"when" is used instead of "if"):
If clause+ main clause:
If you heat water to 100 degrees, it boils.
• If the "if" clause comes first, a comma is usually
used. If the "if" clause comes second, there is no
need for a comma:
• main clause+ if clause
Water boils if you heat it to 100 degrees.
We use the same verb form in each part of a zero
conditional: the simple present tense:
• if clause: if +subject + simple present verb
• main clause: subject + simple present verb
Using the zero conditional
• The zero conditional is used to talk about things which are
always true -- scientific facts, general truths, and so on:
• Example: If you cross an international date line, the time
• Explanation: This always happens, every time you cross a
• If you go 10 meters under water, the pressure increases to
• Explanation: This is basically always true -- the pressure of
10 meters of water equals one atmosphere.
• Phosphorus burns if you expose it to air.
• Explanation: This is a scientific fact -- you can test it in a
Use the conditions and results in the box to complete the phrases below.
Conditions: you've got a headache, you don't wear a crash helmet, you heat it
to 100 ºc, she comes home very late, you leave gates open in the country,
you add sugar
Results: you get pink, A dog bites, the DVD player comes on, Butter melts, it
scratches you, You have more chance of being killed
Water boils if __________________________________
If you mix red and white _________________________________
____________________________________ if you leave it in the sun.
If ____________________________________ , take an aspirin.
If _____________________________________ , it tastes sweet.
__________________________ if you go near its food when it's eating.
If you pull a cat's tail, _______________________________ .
_______________if you don't wear a seat belt.
If you press this button,………………………………………………………………………………
Farmers get very angry if _______________________________________
The First Conditional
The first conditional (also called
conditional type 1) is a structure
used for talking about possibilities in
the present or in the future.
Following I will explain how the first
conditional is formed, and when to
The structure of a first
• A first conditional sentence
consists of two clauses, an "if"
clause and a main clause:
• if clause+ main clause:
If you study hard, you will pass
• If the "if" clause comes first, a comma is
usually used. If the "if" clause comes
second, there is no need for a comma:
• main clause+ if clause:
You will pass the test if you study hard.
We use different verb forms in each part of
a first conditional:
• if clause: if + subject + simple present
• main clause: subject + will + verb
Using the first conditional
• The first conditional is used to talk about
things which are possible in the present
or the future -- things which may
• Example: If it's sunny, we'll go to the
• Explanation: Maybe it will be sunny -that's possible.
• Paula will be sad if Juan leaves.
Explanation: Maybe Juan will leave -that's possible.