Meaning of yāo:
要
(bound form) to demand; to coerce; to want; to need; to ask for; will; shall; about to; need to; should
Tā duì wǒ dàshēng de shuō: “Wǒ yào nǐ mǎshàng líkāi zhèlǐ!”
他对我大声地说:“我要你马上离开这里!”
He shouted at me, "I demand you to leave here immediately!"
Wǒ yào yī bēi shuǐ.
我要一杯水。
I want a glass of water.
Míngtiān wǒmen yào qù Běijīng.
明天我们要去北京。
We will go to Beijing tomorrow.
Wǒ yào qù mǎi xiē shuǐguǒ.
我要去买些水果。
I need to go buy some fruit.
if (same as 要是[yao4 shi5])
Yào shì xiàyǔ, wǒmen jiù dài zài jiālǐ.
要是下雨,我们就待在家里。
If it rains, we will stay at home.
(bound form) important
Zhè gè juédìng hěn yào.
这个决定很要。
This decision is very important.