And as for what they might have developed, I can't even begin to guess.

She could not even begin to guess where they were.

What he had actually seen she could not begin to guess.

I could not begin to guess what the story would be.

He was right: she couldn't begin to guess what his life cost him.

I couldn't begin to guess whom he was talking about.

I cannot begin to guess what our choice would have been.

What he was thinking, she could not begin to guess.

Things he could not even begin to guess the use of.

It was then we began to guess what had happened.