为什麽要

why ...?

→ 为什麽
phrase Uncommon #11,917
why ...? 要 introduces an action someone wants, needs, or intends to do; translate according to context, such as “why do ...?” or “why should ...?”
CH: 为什麽要走?
EN: Why do you have to leave?

为什麽要醒呢

Why wake up?

— 鬼灭之刃:无限列车篇 (2020)

你们为什麽要偷听?

Why are you eavesdropping?

— 白丝带 (2009)

你为什麽要叫停他?

Why did you stop him?

— 潜行者 (1979)

为什麽要哭?

Why are you crying?

— 白丝带 (2009)

为什麽要问我们?

Why ask us?

— 白丝带 (2009)

你为什麽要归还打字机?

Why do you want to return the typewriter?

— 四百击 (1959)

为什麽要带我来?

Why did you bring me here?

— 鬼灭之刃:无限列车篇 (2020)

那他们为什麽要这么做?

Then why would they do that?

— 潜行者 (1979)

他们为什麽要知道?

Why do they need to know?

— 白丝带 (2009)

为什麽要走?

Why do you have to leave?

— 维多利亚 (2015)

维多利亚,你为什麽要这麽做?

Victoria, why did you do that?

— 维多利亚 (2015)

为什麽要这麽做呢?

Why do this?

— 白丝带 (2009)