There are many ways to ask 'why' in Chinese, and there is no one word translation.
Here is a list of how to say WHY around China in eight languages and several dialects of each language. Some places have more than one way to say it. Pronunciation is approximate and not always IPA. Choose the one you like most:
為什麼 wei sheme (Beijing Mandarin)
幹麼 ganma (Beijing Mandarin)
幹什麼 gan sheme (Beijing Mandarin)
為何 wei he (Beijing Mandarin)
為麼兒 wei mer (Jinan Mandarin)
幹麼兒 gae~mar (Jinan Mandarin)
為什麼 wei shengme (Jinan Mandarin)
為啥 wei sa (Xian Mandarin)
因啥 ie~ sa (Xian Mandarin)
為甚 vei seng (Taiyuan Mandarin)
因為甚 ing vei seng (Taiyuan Mandarin)
幹甚 kae~ seng (Taiyuan Mandarin)
為麼事 wei mo sy (Wuhan Mandarin)
做麼事 tsou mo sy (Wuhan Mandarin)
為啥子 wei sa tsy (Chengdu Mandarin, Sichuanese)
做啥子 tsu sa tsy (Chengdu Mandarin, Sichuanese)
做子 tsu tsy (Chengdu Mandarin, Sichuanese)
[怎樣]搞 tcia~ ko (Hefei Mandarin, Anhuiese)
[怎樣]搞的 tcia~ ko te (Hefei Mandarin, Anhuiese)
怎搞 tsen ko (Hefei Mandarin, Anhuiese)
怎搞的 tsen ko te (Hefei Mandarin, Anhuiese)
什們事 senmen sy (Yangzhou Mandarin)
做啥 tso sa (Yangzhou Mandarin)
為啥 whe sa (Suzhou/Shanghai Wu)
作啥 tso' sa, tseu' sa (Suzhou/Shanghai Wu)
啥體 sa thi (Suzhou/Shanghai Wu)
為啥體 whe sa thi (Suzhou/Shanghai Wu)
為何呢 vu 'a nyi, vu ga nyi (Wenzhou Wu)
裝呢 tcyo nyi (Wenzhou Wu)
何解 o kai (Changsha Xiang, Hunanese)
為麼子 wi mo tsy (Shuangfeng Xiang, Hunanese)
做麼子 tseu mo tsy (Shuangfeng Xiang, Hunanese)
為什哩 wi sot li (Nanchang Gan, Jiangxiese)
做什哩 tsu sot li (Nanchang Gan, Jiangxiese)
做乜个 tso mak ke (Meixian Hakka)
樣般 ngiongban (Meixian Hakka)
快世 khe lie, kho lie (Fuzhou N. Min)
幹乜世 kang me lie (Fuzhou N. Min)
做什乇 tso lie no' (Fuzhou N. Min)
為孰事 we su ti (Jianou N. Min)
做孰事 tsa su ti (Jianou N. Min)
是按怎 si antsua~ (Xiamen S. Min, Taiwanese)
為什物 wi simmi~' (Xiamen S. Min, Taiwanese)
創什物 tshong simmi~' (Xiamen S. Min, Taiwanese)
做呢 tso ni~ (Chaoshan S. Min, Chaozhou/Teochew)
點解 tim kai (Guangzhou/Hongkong Yue, Cantonese)
做乜 jou mut, tsou me (Guangzhou/Hongkong Yue, Cantonese)
做乜嘢 jou mutye, tsou meye (Guangzhou/Hongkong Yue, Cantonese)
為乜 wai mi (Yangjiang Yue, Cantonese)
為乜事 wai mi shi (Yangjiang Yue, Cantonese)
做乜 jou mi (Yangjiang Yue, Cantonese)
做乜事 jou mi shi (Yangjiang Yue, Cantonese)
做乜嘢 jou mi ye (Yangjiang Yue, Cantonese)
Notice that the word 'why' is not written with the same characters, all with distinct pronunciations for those characters in each language and dialect.
Courtesy of
www.glossika.com. This represents about 20 easily searchable dialects, but there are more than 50 dialects in the Glossika database, not all searchable yet.