He's in the pub, I'll be bound. 我敢肯定他在酒吧。
She'll be making mischief of some description, I'll be bound.
They'll be up to no good, I'll be bound.
And the three of them left before the clearing up started, I'll be bound.
He won't be back this side of midnight, I'll be bound.
See also: bound adjective (CERTAIN)