What this particle pair is doing, and what a rule-card leaves out

이/가 and 은/는 are not two spellings of the same subject marker. In the teaching frame the Korean assignment uses, 이/가 often marks the person or thing in focus as the actor, and 은/는 often marks a topic or a contrast, including a shift of attention onto the action or onto how two things differ. A card that says '이/가 = subject, 은/는 = topic' is a start, and it will not catch the three error types the assignment actually marks.

This page stays on those three types and on how to practise them. It is not a page about honorific verbs, and it is not a page about sentence-ending forms.

Three error types, with the assignment's own teaching moves

Type one is focus. The assignment's example is a sentence about a famous singer coming to a school festival: if the news is who is coming, 가수가 fits and 가수는 is treated as a mismatch. The same particles can both be grammatical in other focus conditions, so the drill should include few items where both answers are accepted, or students will stop trusting the contrast.

Type two is first mention versus a repeated referent, and it often appears only across two sentences — a teacher gives a gift, then the next sentence talks about that teacher again. The suggested classroom move is to mark first-mention subjects and repeated subjects in a short reading, then ask which particle attaches, and to write a brief note when an exception appears.

Type three is contrast, as in a sentence that likes one kind of meat and not another. The assignment asks for concentrated practice of a few comparison frames, then a writing check. Do not turn the three types into a percentage of all learner errors; the packet does not supply that figure.

Comparisons that help, and ones that overpromise

Japanese は and が are the closest everyday analogue, and teachers who speak both languages already use that pair as a bridge. The bridge breaks when a Korean contrast or a paragraph-level first-mention pattern does not line up with a は/が intuition, so keep a Korean mini-corpus next to the analogy.

English often moves the same information with a/the, with stress, or with a cleft ('it's the singer who…'). Mandarin often moves it with word order, 是…的, or a topic-comment frame, without case particles. Arabic often moves it with definiteness, word order, or an explicit pronoun. Use those as planning notes for the teacher, not as word-for-word substitutes.

Limits

Particle choice also shifts with spoken versus written style and with regional speech. A worksheet key is not a grammar law. Check a current Korean grammar or the National Institute of the Korean Language, and

Sources

1. The CampusDown Korean-education assignment on error types and teaching methods for 이/가 and 은/는, including its three classroom types and its suggested drills, treated as one teaching packet.
2. A current Korean grammar reference, and National Institute of the Korean Language usage notes, for particle environments that go beyond the packet.
3. Short readings and writing checks from the course you actually teach, so that paragraph-level first mention can be seen.

Last updated: November 13, 2026