hadbegun是什么时态
had begun是过去完成时，意为当我到那里时,演出已经开始了.“已经开始”所以用完成时；
My head had begun to ache and my stomach felt funny.
我的头开始疼起来，胃也有些不舒服。
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。