Translate a JSON i18n file into Korean

How Korean reshapes your strings

Korean is verb-final and attaches particles to nouns, and several of them change with the final syllable: 이/가, 을/를, 은/는, (으)로. With a placeholder you cannot know in advance whether the inserted value ends in a consonant, so Korean UIs usually show both forms or lean on a fixed suffix:

• "deleteConfirm": "{item}을(를) 삭제할까요?"
• "joined": "{{name}}님이 참여했습니다" (님 ends in a consonant, so 이 is always correct)

Word order moves placeholders around: “{name} file saved” becomes "{name} 파일이 저장되었습니다", while “Saved to {folder}” puts the folder first. That is expected; what matters is that the same placeholders appear the same number of times.

Korean also counts with classifiers after the number: "파일 {{count}}개" for files, "{{count}}명" for people, "{{count}}건" for records or transactions.

Plurals: only the other category

CLDR gives Korean a single plural category, other. One file and five files follow the same pattern: 파일 1개, 파일 5개. Nothing needs adding, but an other branch must be present everywhere.

• ICU messages: {count, plural, one {# file} other {# files}} comes down in practice to the single useful branch, along the lines of {count, plural, other {파일 #개}}. Korean plural rules never select one; only exact matches such as =0 or =1 are picked.
• i18next suffixes: keys are never translated, so files_one and files_other both stay in the Korean file, but i18next will only read files_other. Check that no plural key in your source lacks its _other variant.

The plural marker 들 is optional and usually left out in interface text, so its absence is not an error.

Speech level, labels and typography

Politeness lives in the verb ending. Two levels dominate software: the formal -습니다 style (저장되었습니다), common in business tools, and the softer polite -어요 style (저장했어요), widespread in consumer apps. Mixing them on one screen stands out straight away.

• Buttons are normally short nouns with no verb ending: 저장 (Save), 취소 (Cancel), 확인 (OK), 삭제 (Delete).
• Punctuation is Western, with no space before ? or !.
• Spaces separate word groups, so spacing around placeholders matters: {{count}}개 is written closed up, while {name} 파일 keeps its space.

What Manuce returns, and what it does not do

You get the same file back: indentation, key order, quotes, comments, line endings, encoding and BOM preserved. Flat or nested JSON and string arrays are handled; only the values change. Placeholders such as {name}, {{count}} and %s, plus ICU plural and select messages, are checked string by string. If a Korean value still differs from the source, for instance a missing placeholder or tag, the source value is kept and the report says so.

Not translated: keys, empty values, URLs, email addresses, numbers, colours, date formats, identifiers and anything marked as non-translatable. A pattern like MM/DD/YYYY therefore stays as it is; showing 2025년 3월 14일 is your code's job.

Manuce does not rename keys, merge a sentence split across several keys, touch your CSS or fonts, or take a glossary. Pricing is based on the words in the values, excluding keys and tags, with a ×1.6 coefficient for Korean.

Preparing the file and checking the output

Before uploading:

• Merge fragmented sentences. “You have”, “{count} messages” and “unread” on three keys cannot become 읽지 않은 메시지 {{count}}개가 있습니다; Korean word order needs a single value.
• Save as UTF-8 and confirm every plural key has its _other form.

In the free sample, look at the speech level, particles after placeholders and counters. Then, in the app:

• Set lang="ko" and provide a Korean fallback font such as Noto Sans KR.
• Try word-break: keep-all, otherwise browsers may break a word between syllables.
• Look for truncated labels: Hangul glyphs are wider than Latin letters.

In practice

1. Merge sentences split across keys and save the file as UTF-8.
2. Upload the JSON: the quote counts the words in the values only.
3. Read the free sample: speech level, particles, counters.
4. Download the Korean file and the report, then drop it into your project.
5. Test the UI with lang="ko", a Korean font and word-break: keep-all.