
Here are some commonly used phrases for greeting others when speaking German.
guten Morgen - good morning/hello
guten Tag - hello
guten Abend - good evening/hello
gute Nacht - good night (used when going to bed)
(auf) Wiedersehen - goodbye
Tschüß - bye/cheerio
NB: 'Tschüß' is less formal than 'auf Wiedersehen'.
In Bavaria (in the south of Germany) and in Austria, you will very often hear 'Gruß Gott' (roughly translated as 'God bless you') instead of 'Guten Tag'.