Even if, even when: dù (cho) … thì … cũng, ngay cả khi

Dù means "even if": whatever happens in the first half, the second half still holds. Put dù before the condition, and cũng or vẫn (still) before the verb of the result: Dù mai trời mưa, em cũng đi. Even if it rains tomorrow, I'm going. In speech, thì often joins the two halves, and có after dù adds weight: Dù có mắc thì em cũng mua. Even if it's expensive, I'll buy it.

Dù cho is a slightly stronger "even if": Dù cho phải đi bộ, em vẫn đi. Ngay cả khi (even when, even if) sounds more careful and suits work and writing: Ngay cả khi nghỉ phép, chị ấy vẫn trả lời email.

With something that is already true, dù means "although": Em vẫn đi làm, dù hơi mệt. That's the job of mặc dù, which has its own page. A possibility after dù means "even if"; a fact means "although".

With a question word, dù means "no matter": dù ai nói gì (no matter what anyone says); that's a separate pattern. And for "even" before one person or thing, use ngay cả … cũng: Ngay cả em cũng biết.