Mixing up "ga" and "wa" sometimes

[Spaztick]

sometimes i notice that instead of using "wa" as a topic particle, I see "ga" instead, like an example on the side kanji - ano hito ga kouchousensei desu.

So, how do you know when to use which?

[Diggity]

I don't have a cat at home

the cat is the topic but not the overall subject marker...

Watashi wa uchi de neko ga arimsen

I know that the particale "ga" is always used with the verbs "iru/aru"

Takeshi is staying at the hotel...

Takeshi-san wa hoteru ga imasu....

Also to say if something (an event) is going on, or to say if you own something...

EDIT - since I just hit the "ga" particle this chapter of the Genki book I am not the best to take advice from... but what I said about "iru/aru" is correct
Nihongo no hon ga arimasen. - I don't have a japanese book.

Doyoubi ni nihongo no kurasu ga arimasen.

There is no Japanese class on Saturday.

[Mukade]

Spaztick wrote:
sometimes i notice that instead of using "wa" as a topic particle, I see "ga" instead, like an example on the side kanji - ano hito ga kouchousensei desu.

So, how do you know when to use which?

This is an extremely complex topic - people have written their PhD thesis on the subtleties of "wa" vs. "ga," so it's not going to be resolved overnight.

But, as a basic rule of thumb, realize that "ga" tends to lend emphasis to what comes before it.

So, in your example of:
ano hito wa kouchousensei desu.
vs.
ano hito ga kouchousensei desu..

The first sentence would be fairly neutral, whereas the second would be emphasizing that that person over there is the principal.

Does that make sense?

[Spaztick]

yea, that makes sense. More emphasis on the subject, got it. Would that be like when you'd want to call attention to something in particular in a sentence, for example? If so, then cool, easy enough. If not...I'll stay away from language studies in college.

[Mukade]

Spaztick wrote:
yea, that makes sense. More emphasis on the subject, got it.

Well, not exactly the subject, but the word that comes directly before it.

So, for example:
私はハンバーガーが食べました。
and
私がハンバーガーを食べました。

In either sentence, が would add emphasis to the noun immediately preceeding が. So the two sentences would be (respectively):
I ate a hamburger. (not a hotdog, not ramen, but a hamburger)
and
I ate a hamburger. (not Jennifer, not Michael...I did)

[KRed]

Spaztick wrote:
yea, that makes sense. More emphasis on the subject, got it.


Well, not exactly the subject, but the word that comes directly before it.

So, for example:
私はハンバーガーが食べました。
and
私がハンバーガーを食べました。

In either sentence, が would add emphasis to the noun immediately preceeding が. So the two sentences would be (respectively):
I ate a hamburger. (not a hotdog, not ramen, but a hamburger)
and
I ate a hamburger. (not Jennifer, not Michael...I did)

Like Mukade said

1 "wa" tends to emphasise what comes after it.

2 "ga" tends to emphasise what comes after it.

A book I read that cleared the diiferences up for me was called "Making Sense of Japanese".

[Spaztick]

Ah, wow. Cool, ok then. Thanks!