How to pronounce 萬年 in Cantonese (5 out of 6):

大約喺 1 萬年
It was about 10,000 years ago.

Cantonese Sentence Breakdown

大約 daai6 joek3
(adverb) About
hai2
in
萬年 maan6 nin4
ten thousand years
cin4
front
forward
ahead
first
top (followed by a number)
future
ago
before
BC (e.g. 前293年)
former
formerly
advance