-아야/어야 하다

RuleVerb/adjective stem + -aya/eoya hada(doeda): marks obligation or necessity, "must / have to." Vowel harmony picks -aya or -eoya.

Curiosity

How do you express obligation, as in "I must do my homework," in Korean?

Intuition

-aya/eoya hada hardens a necessary condition into an obligation: "only if you meet that does it work." It joins -aya/eoya (condition) with hada or doeda ("it comes to be"), saying "you must do so."

Visualization

gada (dictionary) → ga (stem) → gaya hada. ga + aya contracts to gaya, then hada is added.

가다gadadictionary form

Essence

If the stem vowel is a/o use -aya; otherwise -eoya (meogeoya); hada becomes -haeya. Follow it with hada or doeda (gaya haeyo, gaya dwaeyo). The lack of obligation ("you do not have to") is expressed with -ji aneoado doeda or -ado/eodo doeda.

Examples

내일 일찍 일어나야 해요.

I have to get up early tomorrow.

약을 매일 먹어야 돼요.

I have to take medicine every day.

지금 가야 해요.

I have to go now.

Mini-quiz

Attach the obligation -aya/eoya hada to "meokda" (to eat). (stem vowel eo)