到底 (dàodǐ) literally means "to the bottom," and often is used where the speaker wants to get to the bottom of a problem or issue, emphasizing or questioning what the real reason for something is.

到底 as 毕竟 or "in the end"

It is often used like 毕竟, to mean "after all" or "in the end." When used in this way, 到底 is used to emphasize a reason or characteristic the speaker considers to be most important.

Structure 1

Examples

到底是个大老板，出手就是大方。 "He is a high-level boss, after all...")
到底是个高手，这么快就把问题解决了！ "He is a master, after all...")
到底还是孩子，有些事情他不懂是很正常的。 "He is a kid, after all...")

Structure 2

In this structure, A and B are reasons or characteristics, and C is a result or conclusion. For this one, although it's possible to use 到底, 毕竟 is definitely the more common choice, so for examples of this usage, see expressing "after all" with "bijing". 毕竟 can be placed before and after the Subject in this case, but 到底 is usually placed after the Subject.

到底 as 究竟 or "on earth"

到底 can be used to mean "on earth," where it is used to emphasize a question. In this sense, 到底 is similar to 究竟.

Structure

Examples

你到底怎么了？ What on earth is up with you?
到底怎么走？ How on earth do we get there?
快说啊！你男友到底是谁？ Come on! Who on earth is your boyfriend?
你到底说不说？ Are you going to say it or not?
你到底喜不喜欢我？ Do you like me or not?
他们到底离没离婚？ Did they get divorced or not?

Note that 到底 can't appear in an answer to a question. Also, 吗 can't appear in a question formed with 到底 but 没有 can be used instead:

你到底吃了没有？
你到底吃了吗？

到底 as 终于 or "finally"

到底 can be used to mean "finally." In this sense, 到底 is similar to 终于.

Structure

Examples

天气到底暖和起来了。 It‘s finally getting warm.
他到底想明白了。 He finally understood.
经过两年多的努力，我们的项目到底成功了。 Our program finally succeed after we worked on this for over two years.

到底 as 毕竟 or "in the end"

Structure 1

Examples

Structure 2

到底 as 究竟 or "on earth"

Structure

Examples

到底 as 终于 or "finally"

Structure

Examples

See also

Sources and further reading

Books