AnonymousCan you think of a situation where 'was' would prevail -- while maintaining the similar structure?
Yes, for example, the "detective situation".
A detective is going over the details of a crime, explaining his reasoning. In this pattern
If A, B.
is equivalent to
A. Therefore B.
Of course this need not literally be a detective. Any situation involving logical deductions would do as well.
If the thief was on the corner of Elm and Vine at 3 o'clock, he was not at the scene of the crime.
If Anita was not at work Tuesday, she was not aware that Henry had threatened to kill Susan that day.
If the stopped sink was full of water, the faucet was leaking.
_____
Another case is when if is a substitute for whenever. If A, B is equivalent to Whenever A, B.
If she was sad, she took a nap. If she was in a good mood, she went shopping.
If it was rainy, they [stayed / used to stay] inside all day and play games.
If the patient was showing the symptoms of pneumonia, the doctor [prescribed / used to prescribe] antibiotics.
There may be other categories.
CJ