だろ (clipped だろう)

This guy's got a rotten personality, that's probably why he's unpopular with women.

'Still shallow here, huh. My feet touch.' 'It's a pretty gradual slope. Yotsuba can probably still stand too.'

"But we're siblings, aren't we?!" "In name only."

There's no way something this big is going to fit on a bike's rear rack.