Taxis and Buses
Most taxi drivers will not speak English well, so know how to say your destination in Korean, or have it written down on paper. If the driver doesn't understand, call 1330 on your phone to reach a helpline where they can translate for you.
Don't give taxi drivers a street address or the names of small neighborhood buildings-- they will not know these. Use the biggest nearby landmark, like a school, police station, intersection, apartment complex, or shopping center.
If you need to direct the driver to a more specific location, you can say (left) 좌회전 "chai juhn," (right) 우회전 "way juhn," and (straight) 직진 "jeek jeen."
- CITY BUSES
If you plan on using the buses at least sometimes, buy a "My B" card. It's an electronic bus card so you don't have to mess with exact fare in cash (and charges slightly less). You can buy one at many convenience stores for around 2,500 won. You can also use a T-Money card (the same card for the subway in Seoul).
As far as the routes, if you can read Korean, or have a Korean friend to help you, you can consult the bus service website, or get a smartphone app, such as 청주버스. Or, you can call 043-1330 (English-speaking foreigner helpline) for assistance with bus routes/times.