他为何突然改变计划,会上没有人说明。Tā wèihé tūrán gǎibiàn jìhuà, huì shàng méi yǒu rén shuōmíng.No one at the meeting explained why he suddenly changed the plan.
你为何不早点告诉我这件事?Nǐ wèihé bù zǎodiǎn gàosu wǒ zhè jiàn shì?Why didn't you tell me about this earlier?
大家都想知道,这家店为何总是那么多人排队。Dàjiā dōu xiǎng zhīdào, zhè jiā diàn wèihé zǒngshì nàme duō rén páiduì.Everyone wants to know why so many people always queue up at this shop.