How much can it be broadened?

[tufguy]

There is a bridge which is very narrow it has to be broadened.

Can we say the following?

1) How much can it be broadened?

2) How broader can it be made?

3) How wider can it be made?

4) How much can it be widened?

 

[GoesStation]

There is a bridge which is very narrow it has to be broadened.

Can we say the following?

1) How much can it be broadened?

2) How broader can it be made?

3) How wider can it be made?

4) How much can it be widened?

Only "widened" is natural to me. If you insert "much" before wider, number 3 will be OK. Otherwise only #4 works.

 

[bubbha]

I'd be more likely to ask, "How much can it be widened by?"

 

[tufguy]

Only "widened" is natural to me. If you insert "much" before wider, number 3 will be OK. Otherwise only #4 works.

What can be the reply?

The bridge can be widened by 20 feet and lengthened by 50 feet.

 

[GoesStation]

What can be the reply?

The bridge can be widened by 20 feet and lengthened by 50 feet.

That's grammatically correct, though it's answering more than what was asked. You usually don't have any reason to repeat the details of a question when you answer it, so you'd answer "Forty feet" if someone asks How much wider can we make this bridge?

 

[Tdol]

Widen works better than broaden in BrE.