1. CONDITIONAL SENTENCE

2. Conditional Sentence Conditional sentences are sentences
containing actual implications
or suppositional situation and their effects or outcomes that follows previous situation.

3. TYPE 1 If Clause Main Clause If+ Simple Present will future
or infinitive
or modal + infinitive
Example : If the engineers improve solar energy products, they will save our
planet
Fact : It is possible that engineers develop solar products, then our planet
will be saved from running out unrenewable energy
Use : It is possible to fulfill a condition which is given in the if-clause

4. TYPE 2 TYPE 2 If Clause Main Clause If+ Simple Past would + infinitive
could + infinitive
might + infinitive
Example : If the ecologists neglected ecological understanding, the
ecosystems would get worse
Fact : The ecologists do not neglect the ecological understanding.
Therefore, the ecosystem is getting better.
Use : It is theoretically possible to fulfill a condition which is given
in the if-clause

5. TYPE 3 If Clause Main Clause If+ Past Perfect
would + have + past participle
could + have + past participle
might + have + past participle
Example : If the Titanic’s marine engineers had increased the strength
of the ship the ship would not have sunk.
Fact : The Titanic’s marine engineers did not increase the strength
of the ship. Thus, the ship sank.
Use : It is impossible to fulfill a condition which is given in the if
clause

6. TYPE 0 If Clause Main Clause If+ simple present simple present
Example : If you heat water to 100 degrees celcius, it boils
Fact : Water always boils at 100 degrees
Use : It represents general (universal) truth, general fact,
scientific truth