To say “good afternoon” in Taiwanese, you can say “ngo-hiu-h.” This is a common way to greet someone in the afternoon and is considered to be polite and respectful.
There are many other ways to say “good afternoon” in Taiwanese, depending on the region and the context. For example, in southern Taiwan, you might hear people say “m-jing” instead of “ngo-hiu-h.” Ultimately, the best way to learn how to say “good afternoon” in Taiwanese is to listen to how native speakers use the language and practice speaking it yourself.