Introduction to が

The が-particle is a tricky one. It often indicates the grammatical subject of a sentence and is therefore called the subject particle, but this is not always the case. Sometimes the が-particle indicates the object of a sentence, the thing that the verb is influencing.

How to use the が-particle is something Japanese native speakers know from intuition but that makes it harder for other people to learn. Really grasping how it’s used is often a matter of experience. Below you will see a number of instances in which the が-particle is used. As for pronunciation, some speakers pronounce the が-particle ‘nga’ with a little nasal action, but both ‘ga’ and ‘nga’ are acceptable.

Presenting new information & putting focus on a subject

With the が-particle you are presenting new information to the speaker and are focusing attention on that information. For example, compare what you have learned earlier.  The standard sentence for a beginner in Japanese usually goes something like this.   

X は Y です

As you may have read in the lesson on the は-particle, in the above sentence somebody is saying something about X with Y.  An example is:  

これ は りんご です
This is an apple

これ = This one
りんご = Apple
です = Is

The main focus of this sentence is to make clear that it is an apple, so the apple-part is the most important aspect. But what if you want to put emphasis on これ (this one)? For example, if someone points to a banana and says これ は りんごです.

You would of course immediately spring to your feet to correct this mistake by pointing to an actual apple beside the banana and say: これ が りんご です. Replacing the は with が here puts main focus on what you are pointing to. Loosely translated you’re saying ‘No, this is an apple’.

1. Function of が: putting emphasis on the preceding word. 

This holds up when you want to correct someone or answering a question. Say, you were talking about a talented actress and your friend forgot her name. You could say: 

キーラ ナイトレイ が あの はいゆう です.
Keira Knightley is that actress.

あの = That ….
はいゆう = Actor, actress

Another example: 

Person A: だれ が ケーキ を たべましたか
Person B: わたし が たべました. すみません

Person A: Who ate the cake?
Person B: I ate it, I’m sorry.

だれ = Who
ケキ = Cake
すみません = Sorry

Compare the latter instance, with the example below. What if you just wanted to tell somebody you ate cake? You take the same sentence but use は. 

わたし は ケーキ を たべました
I ate cake.

Another example is: 

Always use が when the question word is a subject

When you use words like だれ (who), どこ (where), なに (what) or いつ (when) as a subject in a sentence it is always followed by が and not は. This is a mistake often made, so remember it well. You have to use が because with a question word you do not yet know what the real topic is. Remember that は marks the topic, but when you do not know this, you have to use は. 

Use が in combination with some adjectives 

When you say you like something or something is blue, or funny or interesting, the thing that you are talking about is followed by が. So for example you could say:

A funny thing happens when you use は instead of が in this instance. It conveys a sense of exclusion for the thing you are talking about. This can be pretty harmless in most cases. Take the earlier example of the interesting book. If you use ほんはおもしろいです, you are saying ‘the book is interesting but something else is not’. This is because a は particle can indicate contrast between things. You can read more about this in this article about the は-particle. There is a problem when you make this mistake when trying to give someone a compliment. For example if you say the following: 

When you use が you are really giving a compliment, but when you use は you are making some sort of sneer at the person you are complimenting.