"Goodbye, teacher" in Engpsh is typically said as "Goodbye, (teacher's name)" or simply "Goodbye" when the teacher's name is not known.

The phrase "goodbye" comes from the phrase "God be with ye", which was shortened to "Godbwye" and eventually evolved into "goodbye". The word "goodbye" means "a farewell remark or gesture" and it is used as a way to say farewell to someone.

Examples:

"Goodbye, Mr. Smith"
"Goodbye, class"
"Goodbye, it was nice meeting you"

中文翻译:

"再见,史密夫先生"
"再见,同学们"
"再见,很高兴见到你"