Transportation
Use subways, buses, and taxis and ask for directions in Korea.
Korea's public transportation system is one of the best in the world, and Seoul Metro in particular is highly navigable even for non-Korean speakers. Stations are numbered as well as named, and announcements are in Korean, English, Japanese, and Chinese. The key vocabulary covers transit modes (지하철 subway, 버스 bus, 택시 taxi, 기차 train) and transit verbs (타다 to board, 내리다 to get off, 갈아타다 to transfer).
For asking directions, the phrase pattern is 어떻게 가요? (how do I get there?) attached to a destination: 강남역 어떻게 가요? (how do I get to Gangnam Station?). Modern Korea relies heavily on Naver Map and Kakao Map for navigation; both apps work entirely in Korean but also support English. For taxis, the basic communication is your destination + 가 주세요 (please take me to ~). Kakao Taxi is the Uber equivalent and works in English. Cash and T-money card are both accepted across the system.
~아/어야 하다 — Must / Have to
Verb stem + 아/어야 하다 = must/have to. Same vowel rule applies. 가다 → 가야 해요 (must go), 먹다 → 먹어야 해요 (must eat).
~(으)세요 — Polite Instruction / Suggestion
Verb stem + (으)세요 is a polite way to give directions or instructions. Consonant → 으세요, vowel → 세요. Commonly used when giving directions.