你为何要

why do you

→ 你
phrase Uncommon #12,127
why do you 为何 is a somewhat formal way to say “why.” 要 introduces an intended or contemplated action and does not necessarily mean “have to.”
CH: 你为何要离开?
EN: Why are you leaving?

你为何要射我?

Why are you shooting me?

— 天才一族 (2001)

告诉我,你为何要帮我们?

Tell me, why do you want to help us?

— 荒野大镖客 (1964)

你为何要这样对我们?

Why are you treating us this way?

— 天才一族 (2001)

你为何要救我们?

Why do you want to save us?

— 荒野大镖客 (1964)

你为何要为我做这件事?

Why are you doing this for me?

— 蒲公英 (1985)

你为何要来这里?

Why did you come here?

— 星际旅行2:可汗怒吼 (1982)

你为何要出现在这里呢?

Why are you here?

— 甜蜜的生活 (1960)

你为何要炸掉那张椅子

Why do you want to blow up that chair?

— 虎胆龙威 (1988)

你为何要嘲笑命运?

Why do you mock fate?

— 杀手疾风号 (2022)

你为何要自杀?

Why do you want to kill yourself?

— 天才一族 (2001)

爱玛你为何要这样做?

Emma, why would you do this?

— 甜蜜的生活 (1960)