Japanese you’ll actually hear.
These expressions do not always appear in textbooks, but you will hear them in real conversations, TV, anime, and everyday life.
教科書ではあまり見ない。でも、日本ではよく聞く。
How these words work
Knowing the word type helps you know where to put it in a sentence.
Can describe a person, thing, feeling, or situation.
Often used to give a soft or indirect negative reaction.
Often goes before an adjective, verb, or whole comment.
A regular る-verb: ウケる → ウケた → ウケない.
They end in る, but they conjugate as u-verbs.
Words worth recognizing
Start with these long-established casual expressions rather than short-lived internet slang.
やばい
The meaning changes with context. It can be positive or negative.
めっちゃ
Extremely common in casual conversation.
マジで
You will also hear マジ？ meaning “Seriously?”
微妙
Often softer than saying something is simply “bad.”
だるい
Can describe physical tiredness or “I really don’t feel like doing this.”
めんどくさい
In very casual speech, you may also hear めんどい.
キツい
Useful for physical difficulty, schedules, work, emotions, and more.
ウザい
Saying this directly to a person can sound rude.
キモい
Short for 気持ち悪い. Strong if used about a person.
ダサい
Be careful when commenting on someone’s appearance or taste.
サボる
It ends in る, but it is a u-verb: サボる → サボった → サボらない.
ビビる
It can mean being scared, startled, or intimidated depending on the situation.
ミスる
A casual verb made from ミス. In casual speech, particles such as を are often dropped. ミスする is also common.
パクる
Very casual. It can mean stealing something or copying someone’s idea or work.
ウケる
Grammatically, it behaves like a regular る-verb.
最高 / 最悪
Very common as a short reaction on its own.
Understand first. Use later.
Casual Japanese depends heavily on who you are talking to. With friends, many of these expressions are natural. With customers, teachers, older people, or someone you have just met, neutral Japanese is usually safer.
Widely heard in everyday casual Japanese.
Natural with friends, but not for every situation.
Useful to understand, but can sound rude or harsh.