TYPE ZERO: Something which is always true.
IF + Present simple + Present simple
Example: If the temperature falls below 0'C, water turns into ice.
If you mix blue and red, it becomes purple.
If/when the sun shines, snow melts.
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TYPE ONE: Likely to happen in the future or present. Real or very probable situations...
IF + Present simple - present perfect -present contin. + will, can, may, should, must +bare infinitive
If you don't pay the fine, you will go to the jail.
My mother will help me if she comes home early.
If we cut down the trees, the world's climate will change.
If we don't stop using aerosols, we will destroy ozone layer.
If we recycle waste, we will save naturel resources.
Your turn:
Population/continue to increase/not be enogh food for everyone.
Find alternative energy sources of energy/solve some of our environmental problems.
TIP:
If clause = present simple
Main clause= will future or can,may + bare infinitive
