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) Conditionals Home Page