Inversion of Conditional Sentence

If we had arrived sooner, we could have prevented this tragedy!

• Had we arrived sooner, we could have prevented this tragedy!
• Had we if arrived sooner, we could have prevented this tragedy!

If i had been there, the problem wouldn't have occurred.

• Were I there, the problem wouldn't have occured.

• Had I been there, the problem wouldn't occur.

• Were I there, the problem wouldn't occur.

• Had I been there, the problem wouldn't have been occurred.

Which one is not an inversion?

• Had he not resigned, we would have been obliged to give him the sack.

• Were she to find out that he was seeing someone else, she'd go berserk.

• Should you decide to cancel the contract, please let me know by Friday.

• 'We had scarcely finished lunch when the bell rang for afternoon classes

Only if I had known the difference___________ the more expensive car.

• would I bought

• I would have bought

• would I buy

• would I have bought

Were ________ millions of dollars each year replenishing eroding beaches, the coastline would be changing even more rapidly.

• the U.S. Army Corps of Engineers not to spend

• the U.S. Army Corps of Engineers not spend

• the U.S. Army Corps of Engineers does not spend

• not spending the U.S. Army Corps of Engineers

___________ test positive for antibiotics when tanker trucks arrive at a milk processing plant, according to federal law, the entire truckload must be discarded.

• Should milk

• If milk

• If milk is

• Milk should

............more careful, this accident wouldn't have happened

• Had he been
• He had been
• Was he to be
• He was to be

........she rich, she would buy a big house in New York

• be
• were
• is

____________________________, you would have succeeded in your business.

• If you listened to my advice

• Were you to listen to my advice

• Had you listened to my advice

• As long as you listened to my advice

____________________, he would have been able to pass the exam.

• If he studied harder last year

• Provided he studied hard last year

• Studying harder last year

• Had he studied harder last year