Expressing "how about" with "yaobu"

要不 (yào bù) can have a number of meanings depending on how it is used.

要不 as to mark possible choices

要不 can be used to offer "either/or" choices to others, similar to 或者.

• 你 要不 看书 要不 睡觉 。
• 要不 你 做，要不 我 做，一定 要 做 完。

Another word that can be used in a similar pattern is 要么, with the difference that 要么 can only be used to list the either/or choices available to oneself as well as the choices available to others.

要不 used for suggestions

要不 can be used as an indirect way of giving a suggestion, as the speaker is using 要不 to seek consent of the listener.

• 要不 我们 一起 去 吧。
• 要不 我们 去 吃 湖南 菜 吧，比 川 菜 有 味道。

要不 means otherwise

要不 can also be used to mean otherwise:

• 你 快点 打电话 给 他，要不 他会 很 担心。
• 我 要 打的, 要不 我会迟到。
• 我们 今 晚 需要 收拾 好 行李，要不 明天 来 不 及。

要不然 can be used interchangably with 要不 when it is used as 否则.

Sources and further reading

Books

• Home With Kids1 (家有儿女1) (pp. 50)
• BRIDGE (桥梁 实用汉语中级教程下) (pp. 187)