I can guess part of the reason anyway.

The mages probably guessed part of it.

I guess part where they do the whole assessing the credibility of witnesses thing.

"I thought you might guess part of the truth, Long Tom," he complimented.

There is no way to guess one-tenth part of what may arise under the circumstances.

"She guessed part of it," Louis said.

I'm telling you because you've guessed part of it already, and I don't want you discussing your speculations with anyone.

The manner in which O'Hallihan flinched told Harry he had guessed part of the truth, at least.

Dall must have guessed part of this.

Toshio seemed to have guessed part of it already.