Head of: trưởng (trưởng phòng, hiệu trưởng)

Trưởng means "head, chief". It joins a word for a group or an office to name the person in charge, either before or after that word, and each title has its own fixed order.

Before: trưởng phòng (head of department, the manager you report to), trưởng nhóm (team leader), trưởng ban (head of a committee), trưởng khoa (head of a university faculty).

After: hiệu trưởng (head teacher, principal), lớp trưởng (class monitor), đội trưởng (team captain), bếp trưởng (head chef), bộ trưởng (government minister). This order, with trưởng last, comes from Chinese, and you'll meet it often in the news.

There's no rule you can apply to a new word, so learn each title whole. They're easy to spot, though: a word for a person that starts or ends with trưởng names whoever is in charge. Nhà and viên name a profession or a member; trưởng names the one at the top.

At work, people rarely use the title to someone's face. They call the manager anh or chị with a name, and talk about sếp, the boss: Sếp em khó lắm. My boss is very strict.