Postby Javizy » May 20th, 2009 10:32 pm
Wa and ga serve different grammatical roles and can significantly change the meaning of a sentence if used improperly. For instance, if you use wa in a subordinate clause, it will fail to make sense.
Boku ga iku koen ga ii.
The park I go to is nice.
Boku wa iku koen ga ii.
As for me, the park that goes is nice.
The most basic difference is that wa marks the topic, and ga marks the subject. In the first sentence, I am the subject of the verb 'to go', whereas in the second I am the topic of the sentence, and the rest of it is describing me in some way. Maybe you can or can't tell from this that ga emphasises what precedes it, whereas wa emphasises what follows it.
Boku wa haraimasu.
I'm paying.
Boku ga haraimasu.
I am (the one who is) paying.
In this example, the first sentence simply states what I am doing, whereas the second focuses on who is doing the action (me). This is why you rarely need to say 'watashi wa': we know who you're talking about, we just want to know what you're doing. Similarly, you will often hear people say 'boku ga' when it comes to paying the bill (if you're lucky), since they are saying that they, out of all possible people are going to pay it: we know what's happening, we just want to know who is doing it. A tip I learned from the book 'Making Sense of Japanese' is by thinking of the difference in terms of the following unasked questions.
Dare ga kaerimasu ka?
Who is going home?
Boku ga kaerimasu.
I am going home.
Anata wa nani o shimasu ka?
What will you do?
Boku wa kaerimasu.
I will go home.
This is all kind of off the top of my head, and there's a lot more to it, but maybe it is helpful in some way. If nobody else bothers, maybe I'll fill in the gaps when I get more time. As for 'nante', I wouldn't worry about that for now, it's a JLPT2 expression that can perform a number of grammatical functions that you won't have covered yet, so it's only going to confuse you.