- Nov 5, 2010
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The concept of topic
The difference between は and が is one of the most confusing subject of Japanese language for beginners. Very often we are taught that は is the topic marker and が is the subject marker, but that explanation alone is barely enough. Beginners probably still won't understand why most sentences use は for the subjects while some other use が.
田中先生は化学を教えた。 Tanaka-sensei taught chemistry.
田中先生が化学を教えた。 Tanaka-sensei taught chemistry.
So 田中先生 in the first sentence is the topic, but 田中先生 in the second sentence is the subject? Is there any difference? Well, there's seemingly no difference between these two sentences when you translate them to English like this, but clearly there's something different. Otherwise there would be no need for two particles.
First, let's differentiate "topic" from "subject". The subject here is not exactly the subject of discussion, but the grammatical subject, the nominative, the noun that does the verb. It is an important grammatical element and is grammatically connected to the main verb.
The topic is a bit different. The topic is often the subject, but not necessarily always. The topic is like the theme of the matter, the title of the article, the name of the story. It tells what the sentence is about but is in no way grammatically connected to anything in the sentence.
Like the story or chapter title, it acts like a preface that hints at the content of the narrative, but is somewhat separated from the main body.
"Tanaka-sensei" in "Tanaka-sensei teaches chemistry" is definitely the subject, but "田中先生" in "田中先生は化学を教える" is the topic. You can think of it like this: by saying "田中先生は", the speaker is telling the listener he's going to talk about Tanaka-sensei, and the rest of the sentence is the matter about Tanaka-sensei that he wants to convey.
If that's still too confusing, let's start by looking at the fundamentals of things.
The concept of subject
The reason why the usage of は and が is so confusing is because both are associated with the grammatical "subject". When we try to translate a Japanese sentence into English, it's natural to look for either of these in order to find the "subject" of the sentence. However, this is the root of all the problems. Because we try to fit both は and が into one single concept of "subject", it becomes an issue when we try to do it the opposite direction; we don't know whether to translate that "subject" into は or が.
To help understand は and が better, let's first ditch and forget the English concept of "subject". Suppose you were a kindergartener who knows nothing about language study. Pretend you know nothing about English.
OK, assuming that your head is empty now, let's look at some examples. We know that to make a complete Japanese sentence, nothing more than a verb is required.
教えた。
This is already a complete sentence on its own. Japanese is a highly contextual language. The parties involved will already know what they're talking without having to express everything in words.
EX-1
鈴木: 教えた?
田中: うん、教えた。
- Suzuki asks Tanaka if someone already taught something to someone, and Tanaka replies that someone already did. Both Suzuki and Tanaka know what something is and who someone and someone are, so there's no need to give full information in words (though they can if they want to).
- Tanaka might be teaching chemistry to class 1-C, or mathematics to class 2-G, or cooking to class 3-W. The one who did the teaching might not even be Tanaka. That's something only Suzuki and Tanaka know. From the third person point of view, the only thing we know is Suzuki asks Tanaka if the action of teaching has already been done and Tanaka replies to Suzuki that it has.
EX-2
鈴木: 田中先生は教えた?
田中: うん、教えた。
- Now assume that Suzuki wants to ask Tanaka if the teaching has already been done but fears that merely saying "教えた?" might cause some miscommunication; Tanaka might not understand which teacher Suzuki means. In this case, Suzuki will want to clarify that he wants to know if Tanaka did the teaching. Thus Suzuki will bring up Tanaka as the topic to show that he means Tanaka and not anyone else by adding Tanaka in the sentence and attach は to it.
- We don't know which course is taught or to whom, but it is certain that Suzuki is asking about Tanaka and not anyone else.
EX-3
鈴木: 化学は教えた?
田中: うん、教えた。
- Now Suzuki wants to know if chemistry has already be taught and asks Tanaka for confirmation. Suzuki will want to mention chemistry as the course he's curious about. Thus Suzuki will bring up chemistry as the topic to show that he means chemistry and not mathematics, economics or any other course by adding chemistry in the sentence and attach は to it.
- We don't know which teacher did the teaching or to whom, but it is certain that Suzuki is asking about chemistry.
EX-3.1
鈴木: 化学を教えた?
田中: うん、教えた。
- In this case, instead of は, chemistry is indicated by を particle. Suzuki still wants to know if chemistry has been taught, but chemistry is not the topic anymore. Both Suzuki and Tanaka might already know what they're talking about. Thus the topic of this sentence is omitted like EX-1.
- We don't know which teacher did the teaching or to whom, but it is certain that Suzuki is asking about chemistry.
The difference between EX-3 and EX-3.1 is that, Suzuki in EX-3 wants to make absolutely sure that Tanaka does not take the course as something else other than chemistry, so he uses は to make chemistry the topic, while Suzuki in EX-3.1 merely mentions chemistry without that thought in mind; chemistry is merely a piece of information that elaborate on the action "taught".
If Suzuki is afraid that the job of teaching chemistry might still be not done, he'll bring up chemistry and makes it the topic to show that he's particularly worried about chemistry, and says "化学は教えた?". If chemistry is not the main issue Suzuki worries about, the topic will be something else. For example, if he wants to know whether Tanaka was the one who taught chemistry or not, he'll says "田中先生は化学を教えた?". Of course, if Suzuki thinks Tanaka will realize that he (Suzuki) is asking about him (Tanaka), the 田中先生は part can be omitted.
EX-4
鈴木: 今日は教えた?
田中: うん、教えた。
- In this example, "today" is the topic. Suzuki wants to know if the job of teaching is done for today, not yesterday or the day before yesterday. Thus Suzuki will bring up today as the topic to show that he means today, not other day else. (It might be more clear and sound more natural to say "今日はもう教えた?", but this is for the sake of showing you the difference.)
- We don't know which teacher did the teaching, which course, or to whom, but it is certain that Suzuki wants to know about today's teaching.
The contrastive nature of は
As you can see, the speaker uses は to bring up a topic to show the listener that he means THIS topic and not anything else. It is used to set apart one matter from the rest. Thus the topic particle is contrastive in nature.
鈴木先生は結婚しているが、田中先生は独身だ。
は is used in sentences like this where we bring up two or more things and want to contrast them from one another. This is not unlike previous examples I've shown you. In EX-3 (化学を教えた?), Suzuki wants Tanaka to know he means chemistry and not any other course, and in EX-4 (今日は教えた?), Suzuki wants Tanaka to know he means the teaching of today and not any other day. If you get this idea of "raising a topic" then you'll be able to correctly judge when to use は later.
The identifier が
EX-4.1
鈴木: 今日は田中先生が教えた?
田中: うん、わたしが教えた。
- The point of interest is "today". Suzuki doesn't care about the teaching yesterday or the day before yesterday, so は goes to 今日. He just isn't sure if Tanaka was the one who did the teaching today and wants to confirm it so he uses the identifier particle が to try to identify the one directly responsible for the verb 教えた.
- We know that the teaching happened today, and Suzuki wants to know if Tanaka was the one who did it.
We use が when we wants to identify the one that does the action. Well, we use は to do that too by raising that one that does the action as the topic, but there's a difference.
The difference is, things with particle は become topics, while things with particle が do not.
Confusing? To clarify it:
- は is used when we want to raise something as the topic, the theme, the point of interest. Then we proceed to talk about it.
- が is used when we know what action is going on (the verb) and we want to give the detail about who or what is responsible for that action. It is merely a matter-of-fact piece of information in the sentence. It does not become the topic.
EX-5
鈴木: 誰が教えた?
田中: わたしが教えた。
- This is a wh-question instead of a yes-no question. Suzuki isn't making sure if Tanaka was the one who did the teaching. He now simply asks for the person's name.
- We know that the teaching happened, and Suzuki wants to know who did it.
We don't use は with question words like 誰 because we don't raise something we don't know as the topic. We seek to identify it. The answer doesn't use は either, because Tanaka himself isn't the topic. He is simply giving the information that the one who did the teaching was he.
Now let's compare は and が in other contexts as well.
- わたしはスミスです。
は is used during self introduction as the listener sees the speakers and knows that he exists. The speaker wants to give the listener more information about himself, so he raises himself as the topic then proceed to talk about himself (telling his name, etc.).
- わたしがスミスです。
が is used when we want to identify someone. This is possibly the answer to the question "Who is Smith?". Smith uses が to identify who smith is.
- オレンジは好きです。
This sentence means you like orange, but you use は to raise it as the topic to contrast it with other things. Maybe you don't like fruits in general, but orange is an exception.
- オレンジが好きです。
By saying this, you're merely stating that you like oranges.
- 雨が降っています。
We use が when we want to introduce new things. For example, when you notice that it starts to rain and wants to inform other people about it. The rain doesn't become the topic yet. It is simply a new piece of information that is added to the conversation; you're simply identifying the thing that is falling as rain.
- 雨は降っていません。
However, once you identify it, you can raise it as the topic later. For example, once you notice that the rain you're talking about is in fact not rain but snow, you use は to say this.
- 砂糖は甘いです。
- 雪は白いです。
- チーターは地上で一番速い動物です。
When we talk about the nature or properties of something (like in an encyclopedia), we use は, because those are unique features that distinguish them from other things.
- 雪が赤いです。
However, if something unnatural occurs, we give this new piece of information by using が. This is similar to the above "雨が降っています" example.
- 田中先生は教えましたか。
- 田中先生が教えましたか。
This is a little tricky. "田中先生は教えましたか" is already explained in EX-2; the speaker raises Tanaka as the topic to ensure that the listener knows he's asking about Tanaka and not some other teacher.
Conversely, Tanaka in "田中先生が教えましたか" is not the topic but a piece of information given to detail the action "教えました". To ask "田中先生が教えましたか" is like to ask if 1. the teaching happened and 2. Tanaka did it really took place. The nuance is that the speaker is expressing more doubt and surprise by questioning the whole account.
- 田中先生は化学を教える。
- 田中先生が化学を教える。
And let's end this thread with the very first question I asked: what's the difference between these two sentences?
"田中先生は化学を教える" would be used when both the speaker and the listener already know Tanaka, and the speaker wants to make him the topic. The detail of Tanaka "teaching chemistry" is given to further the conversation.
"田中先生が化学を教える" would be used as an answer to the question, "Who teaches chemistry?" or when we want to introduce the whole account of 1. the teaching happens, 2. chemistry is taught, and 3. Tanaka does it out of the blue.
Summary
We use は to mark the topic of the sentence. Then we proceed to give information related to it. は gives emphasis to other parts of the sentence, because they're the aspect of the topic that we want to discuss.
We use が to identify the cause of the predicate (verb). We knows what happens (verb) and want to give more information about it. が gives emphasis to the word before it, because that is the piece of information we seek to identify.
That's all for now. Comments and questions are always welcomed.
The difference between は and が is one of the most confusing subject of Japanese language for beginners. Very often we are taught that は is the topic marker and が is the subject marker, but that explanation alone is barely enough. Beginners probably still won't understand why most sentences use は for the subjects while some other use が.
田中先生は化学を教えた。 Tanaka-sensei taught chemistry.
田中先生が化学を教えた。 Tanaka-sensei taught chemistry.
So 田中先生 in the first sentence is the topic, but 田中先生 in the second sentence is the subject? Is there any difference? Well, there's seemingly no difference between these two sentences when you translate them to English like this, but clearly there's something different. Otherwise there would be no need for two particles.
First, let's differentiate "topic" from "subject". The subject here is not exactly the subject of discussion, but the grammatical subject, the nominative, the noun that does the verb. It is an important grammatical element and is grammatically connected to the main verb.
The topic is a bit different. The topic is often the subject, but not necessarily always. The topic is like the theme of the matter, the title of the article, the name of the story. It tells what the sentence is about but is in no way grammatically connected to anything in the sentence.
Like the story or chapter title, it acts like a preface that hints at the content of the narrative, but is somewhat separated from the main body.
"Tanaka-sensei" in "Tanaka-sensei teaches chemistry" is definitely the subject, but "田中先生" in "田中先生は化学を教える" is the topic. You can think of it like this: by saying "田中先生は", the speaker is telling the listener he's going to talk about Tanaka-sensei, and the rest of the sentence is the matter about Tanaka-sensei that he wants to convey.
If that's still too confusing, let's start by looking at the fundamentals of things.
The concept of subject
The reason why the usage of は and が is so confusing is because both are associated with the grammatical "subject". When we try to translate a Japanese sentence into English, it's natural to look for either of these in order to find the "subject" of the sentence. However, this is the root of all the problems. Because we try to fit both は and が into one single concept of "subject", it becomes an issue when we try to do it the opposite direction; we don't know whether to translate that "subject" into は or が.
To help understand は and が better, let's first ditch and forget the English concept of "subject". Suppose you were a kindergartener who knows nothing about language study. Pretend you know nothing about English.
OK, assuming that your head is empty now, let's look at some examples. We know that to make a complete Japanese sentence, nothing more than a verb is required.
教えた。
This is already a complete sentence on its own. Japanese is a highly contextual language. The parties involved will already know what they're talking without having to express everything in words.
EX-1
鈴木: 教えた?
田中: うん、教えた。
- Suzuki asks Tanaka if someone already taught something to someone, and Tanaka replies that someone already did. Both Suzuki and Tanaka know what something is and who someone and someone are, so there's no need to give full information in words (though they can if they want to).
- Tanaka might be teaching chemistry to class 1-C, or mathematics to class 2-G, or cooking to class 3-W. The one who did the teaching might not even be Tanaka. That's something only Suzuki and Tanaka know. From the third person point of view, the only thing we know is Suzuki asks Tanaka if the action of teaching has already been done and Tanaka replies to Suzuki that it has.
EX-2
鈴木: 田中先生は教えた?
田中: うん、教えた。
- Now assume that Suzuki wants to ask Tanaka if the teaching has already been done but fears that merely saying "教えた?" might cause some miscommunication; Tanaka might not understand which teacher Suzuki means. In this case, Suzuki will want to clarify that he wants to know if Tanaka did the teaching. Thus Suzuki will bring up Tanaka as the topic to show that he means Tanaka and not anyone else by adding Tanaka in the sentence and attach は to it.
- We don't know which course is taught or to whom, but it is certain that Suzuki is asking about Tanaka and not anyone else.
EX-3
鈴木: 化学は教えた?
田中: うん、教えた。
- Now Suzuki wants to know if chemistry has already be taught and asks Tanaka for confirmation. Suzuki will want to mention chemistry as the course he's curious about. Thus Suzuki will bring up chemistry as the topic to show that he means chemistry and not mathematics, economics or any other course by adding chemistry in the sentence and attach は to it.
- We don't know which teacher did the teaching or to whom, but it is certain that Suzuki is asking about chemistry.
EX-3.1
鈴木: 化学を教えた?
田中: うん、教えた。
- In this case, instead of は, chemistry is indicated by を particle. Suzuki still wants to know if chemistry has been taught, but chemistry is not the topic anymore. Both Suzuki and Tanaka might already know what they're talking about. Thus the topic of this sentence is omitted like EX-1.
- We don't know which teacher did the teaching or to whom, but it is certain that Suzuki is asking about chemistry.
The difference between EX-3 and EX-3.1 is that, Suzuki in EX-3 wants to make absolutely sure that Tanaka does not take the course as something else other than chemistry, so he uses は to make chemistry the topic, while Suzuki in EX-3.1 merely mentions chemistry without that thought in mind; chemistry is merely a piece of information that elaborate on the action "taught".
If Suzuki is afraid that the job of teaching chemistry might still be not done, he'll bring up chemistry and makes it the topic to show that he's particularly worried about chemistry, and says "化学は教えた?". If chemistry is not the main issue Suzuki worries about, the topic will be something else. For example, if he wants to know whether Tanaka was the one who taught chemistry or not, he'll says "田中先生は化学を教えた?". Of course, if Suzuki thinks Tanaka will realize that he (Suzuki) is asking about him (Tanaka), the 田中先生は part can be omitted.
EX-4
鈴木: 今日は教えた?
田中: うん、教えた。
- In this example, "today" is the topic. Suzuki wants to know if the job of teaching is done for today, not yesterday or the day before yesterday. Thus Suzuki will bring up today as the topic to show that he means today, not other day else. (It might be more clear and sound more natural to say "今日はもう教えた?", but this is for the sake of showing you the difference.)
- We don't know which teacher did the teaching, which course, or to whom, but it is certain that Suzuki wants to know about today's teaching.
The contrastive nature of は
As you can see, the speaker uses は to bring up a topic to show the listener that he means THIS topic and not anything else. It is used to set apart one matter from the rest. Thus the topic particle is contrastive in nature.
鈴木先生は結婚しているが、田中先生は独身だ。
は is used in sentences like this where we bring up two or more things and want to contrast them from one another. This is not unlike previous examples I've shown you. In EX-3 (化学を教えた?), Suzuki wants Tanaka to know he means chemistry and not any other course, and in EX-4 (今日は教えた?), Suzuki wants Tanaka to know he means the teaching of today and not any other day. If you get this idea of "raising a topic" then you'll be able to correctly judge when to use は later.
The identifier が
EX-4.1
鈴木: 今日は田中先生が教えた?
田中: うん、わたしが教えた。
- The point of interest is "today". Suzuki doesn't care about the teaching yesterday or the day before yesterday, so は goes to 今日. He just isn't sure if Tanaka was the one who did the teaching today and wants to confirm it so he uses the identifier particle が to try to identify the one directly responsible for the verb 教えた.
- We know that the teaching happened today, and Suzuki wants to know if Tanaka was the one who did it.
We use が when we wants to identify the one that does the action. Well, we use は to do that too by raising that one that does the action as the topic, but there's a difference.
The difference is, things with particle は become topics, while things with particle が do not.
Confusing? To clarify it:
- は is used when we want to raise something as the topic, the theme, the point of interest. Then we proceed to talk about it.
- が is used when we know what action is going on (the verb) and we want to give the detail about who or what is responsible for that action. It is merely a matter-of-fact piece of information in the sentence. It does not become the topic.
EX-5
鈴木: 誰が教えた?
田中: わたしが教えた。
- This is a wh-question instead of a yes-no question. Suzuki isn't making sure if Tanaka was the one who did the teaching. He now simply asks for the person's name.
- We know that the teaching happened, and Suzuki wants to know who did it.
We don't use は with question words like 誰 because we don't raise something we don't know as the topic. We seek to identify it. The answer doesn't use は either, because Tanaka himself isn't the topic. He is simply giving the information that the one who did the teaching was he.
Now let's compare は and が in other contexts as well.
- わたしはスミスです。
は is used during self introduction as the listener sees the speakers and knows that he exists. The speaker wants to give the listener more information about himself, so he raises himself as the topic then proceed to talk about himself (telling his name, etc.).
- わたしがスミスです。
が is used when we want to identify someone. This is possibly the answer to the question "Who is Smith?". Smith uses が to identify who smith is.
- オレンジは好きです。
This sentence means you like orange, but you use は to raise it as the topic to contrast it with other things. Maybe you don't like fruits in general, but orange is an exception.
- オレンジが好きです。
By saying this, you're merely stating that you like oranges.
- 雨が降っています。
We use が when we want to introduce new things. For example, when you notice that it starts to rain and wants to inform other people about it. The rain doesn't become the topic yet. It is simply a new piece of information that is added to the conversation; you're simply identifying the thing that is falling as rain.
- 雨は降っていません。
However, once you identify it, you can raise it as the topic later. For example, once you notice that the rain you're talking about is in fact not rain but snow, you use は to say this.
- 砂糖は甘いです。
- 雪は白いです。
- チーターは地上で一番速い動物です。
When we talk about the nature or properties of something (like in an encyclopedia), we use は, because those are unique features that distinguish them from other things.
- 雪が赤いです。
However, if something unnatural occurs, we give this new piece of information by using が. This is similar to the above "雨が降っています" example.
- 田中先生は教えましたか。
- 田中先生が教えましたか。
This is a little tricky. "田中先生は教えましたか" is already explained in EX-2; the speaker raises Tanaka as the topic to ensure that the listener knows he's asking about Tanaka and not some other teacher.
Conversely, Tanaka in "田中先生が教えましたか" is not the topic but a piece of information given to detail the action "教えました". To ask "田中先生が教えましたか" is like to ask if 1. the teaching happened and 2. Tanaka did it really took place. The nuance is that the speaker is expressing more doubt and surprise by questioning the whole account.
- 田中先生は化学を教える。
- 田中先生が化学を教える。
And let's end this thread with the very first question I asked: what's the difference between these two sentences?
"田中先生は化学を教える" would be used when both the speaker and the listener already know Tanaka, and the speaker wants to make him the topic. The detail of Tanaka "teaching chemistry" is given to further the conversation.
"田中先生が化学を教える" would be used as an answer to the question, "Who teaches chemistry?" or when we want to introduce the whole account of 1. the teaching happens, 2. chemistry is taught, and 3. Tanaka does it out of the blue.
Summary
We use は to mark the topic of the sentence. Then we proceed to give information related to it. は gives emphasis to other parts of the sentence, because they're the aspect of the topic that we want to discuss.
We use が to identify the cause of the predicate (verb). We knows what happens (verb) and want to give more information about it. が gives emphasis to the word before it, because that is the piece of information we seek to identify.
That's all for now. Comments and questions are always welcomed.
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