房东提高租金前没有事先通知我们。

Fángdōng tígāo zūjīn qián méiyǒu shìxiān tōngzhī wǒmen.

The landlord didn't inform us before raising the rent.

航空公司有责任在航班取消前事先通知乘客。

Hángkōng gōngsī yǒu zérèn zài hángbān qǔxiāo qián shìxiān tōngzhī chéngkè.

It is the responsibility of the airline to inform passengers before cancelling a flight.

请事先告诉我你的计划。

Qǐng shìxiān gàosù wǒ nǐ de jìhuà.

Please let me know your plan in advance.