The topic marker: 은/는¶

What the heck is a topic marker?¶

The topic marker is one of the neatest parts of Korean grammar. Analogously to the subject marker 이/가, you use 은 after a consonant and 는 after a vowel.

From a linguistics point of view, topic markers are pretty rare and you won't be used to them even coming from another language with case. Wikipedia has the following to say:

A topic marker is a grammatical particle used to mark the topic of a sentence. It is found in Japanese, Korean, Kurdish, Quechua, Ryukyuan, Imonda and to a limited extent Classical Chinese. It often overlaps with the subject of a sentence, causing confusion for learners, as most other languages lack it. It differs from a subject in that it puts more emphasis on the item and can be used with words in other roles as well. Thus, the subject and the object are not always the topic and comment but often have straightforward relationships to them.

The best translation that I can say is that "X은/는" roughly means "As for X…". To try and illustrate what makes the topic marker so neat, I'm first going to show you examples where the topic and subject coincide, and then examples where they don't.

I think the thing I want to drive home is that the topic and subject are a bit orthogonal; they don't a priori have to coincide. However, it's probably common in real life that the main focus of a sentence happens to also be the subject of the sentence, causing the two to be confused often.

But there's no linguistic reason why that has to be true. There are examples where the topic marker is instead on the object, and examples where it's used to set context by marking a noun that is neither the grammatical subject nor object (so it is "floating" above the sentence).

Topic markers on subjects (replacing 이/가)¶

As I said, the most common case is that the topic is the sentence subject; in that case the topic marker replaces 이/가. For example, the earlier example sentences

could be rewritten as

In practice, this means when you have a normal everyday sentence, you often need to decide whether to grace the subject with an upgrade from 이/가 to 은/는. This seems to be tough to give airtight rules for, but some rules of thumb:

• 이/가 is more common for newly introduced nouns (sort of like English "a") whereas 은/는 is more common for already-introduced nouns (sort of like English "the")
• 은/는 can be used even for newly introduced nouns in order to emphasize some sort of contrast.

Topic markers on objects (replacing 을/를)¶

Here's a simple example where the topic marker applies to the object instead.

Marking "math" as the topic indicates this is in contrast, perhaps, to other subjects that the speaker might know about.

Topic markers used to set context¶

I think it's better if I just start by throwing some examples at you. Here are several examples where the topic is 저(는), and then a sentence with a different subject and an adjective (remember Korean adjectives are always intransitive).

These examples are meant to showcase how topic markers are really flexible. All of these are simple sentences about the speaker. In English, you use all sorts of different ways of attaching yourself; the examples show a lot of different patterns to work around this:

• possession¹ ("my day")
• using a certain auxiliary word ("math is difficult for me" or "I'm scared of wolves")
• outright rephrasing the grammar structure ("I like cats", "I am tall").

It's jarring to me that in English you need so many different constructions. In Korean, it's much simpler: just use 은/는 to set the topic. So the topic marker gives you a single unified way to create contextual sentences. That's what makes it so expressive.

Finally, one example with a topic, subject, and an object:

Harder examples (TODO)¶

• Example where the topic marker is on an adverb
• Example where the topic marker is on another particle