Chinese phrase
可以，但要〜 ké yǐ dàn yào 〜
Meaning
Sure but you need to ___
When to use it
It agrees to a request but adds a condition. The unfinished part states what must happen, often in a friendly, practical tone.
Example dialogue
我可以借你的车吗？ wǒ ké yǐ jiè nǐ de chē ma
Can I borrow your car?
可以，但要把油加满再还我。 ké yǐ dàn yào bǎ yóu jiā mǎn zài huán wǒ
Sure, but fill up the tank before you return it to me.