Chinese phrase
请在〜之前回复 qǐng zài 〜 zhī qián huí fù
Meaning
Please reply by ___
When to use it
This politely asks someone to reply by a stated deadline. It is common in messages and other polite requests, and sounds respectful rather than forceful.
Example dialogue
请在下周一之前回复，可以吗？ qǐng zài xià zhōu yì zhī qián huí fù ké yǐ ma
Could you please reply by next Monday?
没问题，我会在下周一之前回复您。 méi wèn tí wǒ huì zài xià zhōu yì zhī qián huí fù nín
No problem, I'll reply by next Monday.