chào

Etymology
. and. (Nguyễn Văn Khang. Từ ngoại lai trong tiếng Việt, 2007)

, which also means both "hello" and "goodbye".

Verb

 * 1)  to greet, salute, say hello or goodbye to

Usage notes

 * As with, a subject is not required if it is said by the person who is doing the greeting. However, it might be considered bad form for young children not to use their appropriate pronoun for a subject.
 * Chào is the only greeting that is genuinely used. Xin chào is rather stiff and unrealistic, mostly appropriate on television or at formal events. There isn't any variant used based on the current time of day, although an artificial expression such as may be heard in certain contexts, such as songs, prose or poetry, and especially relevant in language teaching. Unironically saying chào buổi sáng, however, might make one sound awkward and potentially pretentious.
 * Chào is rarely ever said in isolation. Most of the time, a following pronoun or kinship term is required. For example,, , , etc.). These phrases, or just chào by itself, can be followed by a final particle, such as or.

Interjection

 * 1) alas; ah