Center for Japanese Language Education,the University of Tokyo

Particle "wa" and "information structure"

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On this site I will talk about the particle "wa". "Wa" is the most characteristic particle in Japanese, because it is closely connected with how sentences are made in Japanese, especially with the way of presenting information. Together with "wa", I will briefly refer to "ga" which is said to be similar to "wa"..

1. What is a "case marker"?; "Wa" is not a case marker

On the site "What are the characteristics of Japanese?" I explained as follows

(a) Tanakasan wa ocha o nomimashita. (Tanaka drank tea.)
(b) Tanakasan wa Satosan to kissaten de ocha o nomimashita. (Tanaka drank tea at a coffee shop with Sato.)

"O" in "Ocha o" in sentence (a) and (b) is the object marker, which marks "ocha" as object. "To" in sentence (b) "Satosan to" is "with" in English, so "Satosan to" means "with Sato". "De" as in "kissaten de" is similar to "at", so "kissaten de" can be translated as "at a coffee shop". As you can see, the particle marks the noun's role within the sentence. "Ocha" is the object, "Satosan" is the partner of the action, "kissaten" is the place of the action, and these are each the nouns' "role".

The role is called the "case" in grammatical terms. "O", "to", and "de" are particles that mark cases, so they are called case particles or case markers.

On the site "What are the characteristics of Japanese?" I explained that "wa" is the subject marker (this means that it is a kind of case marker). However, I mentioned "at this stage, I will refrain from further explanation". In fact, "wa" is not a subject marker or a case marker. At the time I needed to explain as I did, but on this site I will explain about the real nature of "wa" in detail.

2. Three different sentences telling the same fact

"Ga" is another particle besides "wa" that marks the subject. Regarding sentence (a), you can use "ga" instead of "wa" as in the following sentence (1). I will indicate (a) again as sentence (2).

(1) Tanakasan ga ocha o nomimashita. (Tanaka drank tea.)
(2) Tanakasan wa ocha o nomimashita. (Tanaka drank tea.)

Both sentences are translated the same way in English or Chinese. Consequently, many non-native speakers find it difficult to distinguish the slight difference between (1) and (2), or in other words the difference of "wa" and "ga". However, by analyzing it from the linguistics point of view, the difference of "wa" and "ga" is very clear. To explain this, I will add another sentence below.

(3) Ocha wa Tanakasan ga nomimashita. (Tanaka drank tea.)

Let me explain sentence (3) briefly. (3) is telling the same fact as sentence (1) and (2), "Tanaka drank tea". "Ocha" is the object and "Tanakasan" is the subject. In (3), "wa" follows the object "ocha" and "ga" follows the subject "Tanakasan". You can now see that "wa" is not a subject marker. Then what is the function of "wa"?

(1), (2) and (3) all tell the same fact, but how they it is told is different. "Wa" is related to this difference (whether there is "wa" or not, and which noun is followed by "wa").

3. "Wa" is a topic marker

Let's compare (2) and (3) to make this clear.

(2) Tanakasan wa ocha o nomimashita. (Tanaka drank tea.)
(3) Ocha wa Tanakasan ga nomimashita. (Tanaka drank tea.)

The difference between the above two sentences is that (2) is talking about "Tanakasan" and (3) is talking about "ocha". In another words, (2) is answering the question "What did Tanaka drink?" (or "What did Tanaka do?") and (3) "Who drank tea?".

Neither sentence does not necessarily need a question, but the main interest is "Tanakasan" in (2), and "ocha" in (3). In cases such as (2), sometimes "Tanakasan" and "Suzukisan" might be contrasted, and in (3) "tea" and "coffee" might be contrasted, but whether it is a contrast or not, the essential difference between (2) and (3) is the topic. The topic in (2) is "tanakasan", and "tea" in (3).

The expression "X wa..." indicates that X is the topic, so the speaker is talking about or making questions about X, and this is the function of "wa". You can let the listener know that you are talking about X by saying "X wa...", and this function is called the topic marker in the field of linguistics. There are languages that have a topic marker and those that do not.

4. The < Information structure > of sentences in Japanese

Some of you may want to know what is the difference between the topic and the subject. "Tanakasan" is both a subject and a topic in (2). On the other hand, "ocha" is the topic but not the subject in (3). It is an object, isn't it? Topic and subject could be either the same or different. Even if it is the same, the idea is different.

As a matter of fact, it is often the case that the same word is used as a subject and also as a topic in any language, but you can find the individual characteristics of each language in the cases where the subject and topic are different. Some languages put weight on the subject but others on the topic, when constructing a sentence. For example, English is a language that puts the subject at the beginning of a sentence normally. On the other hand, Japanese puts more weight on the topic. It first presents the topic, and then talks about it. This is the < information structure > of the Japanese language. This is why "ocha" is placed at the beginning of the sentence when one talks about "ocha" even though it is an object. Further. one uses "wa" to indicate that it is the topic, and constructs the sentence as in (3). In such a language, the role of the topic marker is important. "Wa" is a topic marker that is very much related to the Japanese sentence structure or < information structure >.

5. "Ga" is a case marker

It is clear about "wa", so now let's look at "ga". I will again compare sentences (1) and (2).

(1) Tanakasan ga ocha o nomimashita. (Tanaka drank tea.)
(2) Tanakasan wa ocha o nomimashita. (Tanaka drank tea.)

I have already explained that (2) tells "What Tanaka drank is ... (or, "What Tanaka did is...")". On the other hand, (1) tells "What happened is...", or "Who drank the tea is...". Anyway, "Tanakasan" is not the topic in (1). "Ga" is not a topic marker, it is a case marker. It was possible to bring the object to the beginning of the sentence in (3) because the case marker "ga" followed "Tanakasan" which prevented "ocha" from being misunderstood as the subject.

I think it is quite clear now that "wa" is a characteristic particle that is related to the Japanese sentence structure (especially the < information structure >). To be proficient in the usage of "wa" is to be proficient in Japanese.

There are many more points to refer to regarding "wa", or differences between "wa" and "ga", but here I focused only on the most basic point.

For advanced learners who want to know more details, please refer to my report 'On wa and ga' ("UP" [PR magazine of the University of Tokyo Press] Vol. 31 No. 12, December 2002, written in Japanese).

Points: Advise for Japanese learners (4)
"X wa..." is the sign telling that "I am going to talk about X." ("Wa" is the topic marker.)
Tanakasan wa ocha o nomimashita.
← What Tanaka drank (did) is...
Ocha wa Tanakasan ga nomimashita.
← Who drank the tea is...
Tanakasan ga ocha o nomimashita.
← What happened is ...
← Who drank the tea is...
2. Start studying with the polite style out of the two styles.
Ikimasuka? - Hai, ikimasu. (polite style)
Iku? - Un, iku. (casual style)
(Are you going? - Yes, I'm going.

* The contents of this page are almost the same as the article "Learn the characteristics of Japanese language and study effectively (4) : Particle wa and " by KIKUCHI Yasuto (Professor of the International Center, the University of Tokyo), to appear in International Center News, The University of Tokyo, No.36.

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