QUOTE(lamplight @ Jan 20 2008, 04:16 AM) [snapback]3437194[/snapback]
i sometimes can and can't
it's sometimes hard to differentiate between vietnamese chinese korean filipinos japanese cambodian thai and laotians
how do you know where a person comes from specifically in asia?
i know it has to do something with their facial features
what the the similarities and differences?
thanks in advance

Japanese might stand out as the easiest to tell. Lighter skinned than Koreans so I have noted, but please don't take this as anything more than a personal observation of mine when teaching different classes of very small sample groups. As with other observations below, although I still have to think of them yet.
Many Chinese people have a unique look, and again that similar skin tone (perhaps) as Japanese although very different features. Maybe Japanese people are notably the most unique, but just an observation on a few people I've met, and not meaning to shed negative nor positive light.
Although there is a look that seems Thai, and maybe the same for the I've known for the dozen or so Filipino blokes I've known, the SEA features are quite difficult to determine. Indonesians often have a certain look, although it's a bit like asking if you can tell the difference between Italians, Greek and Spanish - English, Dutch and American - Argentinian, Chiliean, and Peruvian. All very much based on the few people that we might get to know personally and actually find out their origin, and a Venuzuelan at 20 might more resemble a Mexican at 50.
Still, Japanese, Chinese and Korean do tend to share certain attributes on features. Please accept this as a very personal opinion and in no way an empirical fact. The most reliable means of working out someone's natoinality is probably still to just ask them where they're from.