Korean has speech that raises the listener. Which style is safe to use by default with someone you've just met, an elder, or a shop clerk?

Jondaenmal — speech using endings like ~yo or ~seumnida — exists in Korean as a built-in way to signal respect toward someone whose age, status, or closeness to you isn't yet established, so defaulting to it with strangers, elders, or service staff avoids any risk of sounding presumptuous. It can be dialed back to casual speech later, once a relationship is clearly close.

Banmal (casual speech) is reserved for close friends, peers, or people younger than you who've explicitly allowed it, so using it with someone you just met can come across as disrespectful. Dialect is a regional variation of pronunciation and vocabulary, not a politeness level.

Many Korean dramas build entire plot tensions around the moment two characters switch from jondaenmal to banmal, since that shift itself signals a change in emotional closeness.