Conditional Sentences - Type 0

TYPE 0 : Cause and Effect - Habitual results - Advice/Commands


This type of conditional is used to talk about general truths. It can also be used to describe cause and effect , facts , habitual reactions , commands and advice . The most commonly used form is ;
If + Simple present , Simple Present


If you heat the metal , it expands. (cause & effect)
I get angry if someone shouts at me. (habitual reaction)
If you boil water , it evaporates. (cause & effect)
I usually eat a few biscuits if I get hungry before lunch time. (habitual reaction)
If you go round the world , you return to the same point. (general truth)


"when" can be used instead of "if" in this type.


If it is hot , I wear thin clothes. (= When it is hot, I wear thin clothes.)
The door opens if you turn the switch ( = when you turn the switch the door opens)
Advice and commands are also expressed in this type (Note : They are considered Type-1 in some books)


If you do not want to put on weight don't eat too much . (advice)
Don't wait for me if I am late this evening. (command)
If you feel sick , see the doctor. (advice)
Stop smoking and take up a sport if you want to keep fit. (advice)