Reactions & Exclamations
React naturally to surprising news the way Koreans actually do — 대박, 헐, 진짜?/진짜요?, 아이고, 완전 좋아요 — and know which ones are safe with strangers.
Reaction words have their own register rules
Exclamations like 헐 and 대박 are pure 반말 territory — they're casual, spoken reflexively among friends or typed in comment sections, and they can sound unprofessional or even rude in a formal setting like a job interview or with your professor. 아이고 is the exception: it's used by literally everyone, from grandmothers to gen-z, so it's always safe. When unsure, add 요 — 진짜? becomes 진짜요?, instantly polite.
The single most universal Korean reaction word — works for good news, shocking news, or just something impressive. Casual (반말); with strangers or in formal settings, a plain '와' or '정말요?' is safer.
Adding 요 to a bare reaction
Some reaction words aren't full verbs — they're just short interjections, and 요 can be tacked directly onto them to make them polite. 진짜 ('really/seriously') becomes 진짜요? the same way 사랑해 became 사랑해요 in the last lesson, just in the other direction: here you're adding 요 rather than dropping it.
반말 — casual. Perfect for a friend telling you gossip.
The polite version — safe with a coworker, a teacher, or anyone you've just met. Same shock, more respect.
Pure slang — a sound of being genuinely stunned, more intense than 진짜?. Only among friends or online; never in front of your professor or boss. Think of it as Korean's version of a jaw-drop emoji.
The all-purpose sigh — grandmothers say it dropping groceries, kids say it missing a shot in a game. Unlike 헐, 아이고 is genuinely safe in almost any company, casual or formal.
완전 means 'totally/completely' and works as an intensifier before almost any adjective. Because this keeps its 요, it stays 해요체 — safe with anyone, even while being enthusiastic.
A close friend surprises you with news — reacting in real time (original scene, casual speech)
Say it out loud
Listen, then repeat aloud. Matching the rhythm matters more than perfection.