Write a message to your manager asking for leave: dates, reason, and how your work will be covered.

Formal tone. Call your manager ANH or CHỊ — Vietnamese offices use family terms, not job titles, even in formal writing.

Softening patterns: «Em xin phép...», «Không biết anh có thể... không ạ ?»

Cultural note: state the reason briefly, then focus on how the work will be handled. Long personal explanations are not expected.