Work email
Before
Dear Manager, I am writing to kindly ask you that whether it is possible to extend deadline of the report to next Monday, because recently I am very busy for another urgent project. Hope to get your understanding. Thanks a lot.
After
Hi [Manager], could we extend the report deadline to next Monday? I'm currently tied up with another urgent project. Thanks for understanding.
The request, the new deadline, and the reason all survive — the sentence structure becomes native English.