If Clause Type I
if + Simple Present, will-Future
Type I indicates what will happen, provided that a certain situation is given.
( PRESENT SITUATION, FUTURE CONSEQUENCE )
If you send your order by fax, we will deliver the goods immediately.
If you invite me for lunch, I will help you with your presentation.
If Clause Type II
if + Simple Past, would + infinitive
Type II indicates what could happen if a present situation were different.
( IMAGINARY SITUATIONS )
If we had more employees, we would work more efficiently.
If we delivered poor quality, we would not be the leading company in our business.
If Clause Type III
if + Past Perfect, would + have + past participle
Type III indicates what could have happened in the past if a situation had been different then.
( REGRETS )
If you had read the paper, you would have seen the advertisement.
If I had taken the bus, I would have been late.
|if clause||main clause|
|I||Simple Present||will-future (or Modal + infinitive)|
|II||Simple Past||would + infinitive *|
|III||Past Perfect||would + have + past participle *|
Examples (if-clause at the beginning)
|type||if clause||main clause|
|I||If I study,||I will pass the exam.|
|II||If I studied,||I would pass the exam.|
|III||If I had studied,||I would have passed the exam.|