Conjugation of verbs by formality levels, full algorithm¶

In the last section we only conjugated words ending in 하다. Here's how to conjugate everything else. This just comes down to memorizing a list of rules, which might seem long but isn't actually that bad.

(None of the examples on this page are irregular; we'll get to that later.)

Here's the summary of the suffixes for each level:

Diary¶

• Adjectives don't change at all; they stay in dictionary form.
• For verbs, replace 다 with 는다 if the stem ends in a consonant, and with ㄴ다 (attaching the ㄴ to the last syllable) if it ends in a vowel.

Casual¶

Remove 다, then follow the first rule that applies:

• If the stem ends in 하, change 하 to 해.
• If the stem ends in vowel ㅡ, replace ㅡ with ㅏ if the previous syllable's vowel is ㅏ/ㅗ, and with ㅓ otherwise (including if there is no previous syllable).
• If the last vowel is ㅏ/ㅑ/ㅗ, add ㅏ. Then, if the stem ended with a vowel, do these merges:
  • ㅏ+ㅏ=ㅏ (absorb).
  • ㅗ+ㅏ=ㅘ.
• If the last vowel is anything else, add ㅓ. Then, if the stem ended with a vowel, do these merges:
  • ㅣ+ㅓ=ㅕ.
  • ㅜ+ㅓ=ㅝ.
  • ㅚ+ㅓ=ㅙ.
  • ㅓ/ㅕ/ㅐ/ㅔ+ㅓ=ㅓ/ㅕ/ㅐ/ㅔ (absorb).
  • Any other vowel doesn't merge.

Polite¶

• Add 요 to the casual form.

Formal¶

• Replace 다 with 습니다 if the stem ends in a consonant, and with ㅂ니다 (attaching the ㅂ to the last syllable) if it ends in a vowel.