The window frames had begun to warp.
窗框已经开始变形。
He had begun to feel sleepy.
他已觉得困了。
The gold colouring had begun to rub off.
金黄色已经开始剥落了。
She had begun to be a little bored with novel writing.
她开始对写小说有些厌倦了。
The blood had begun to cake and turn brown.
血开始结块变黑。