こんなデカイのがチャリの荷台に乗るわけないだろ。
There's no way one that big is going to go on a bike's luggage rest.
あいつでかいことばかり言ってるけど、そのうちぼろを出すよ。
He's always talking like a big shot, but it won't be long before all his faults are exposed.
