O vs Wa in Japanese
When does one use the copulas "ga" vs "wa" vs "o" in Japanese grammar?
Very basic, but here are some sample sentences:
[WA] in general:
Wa is a topic marker:
Watashi WA sono Chocolate wo Tabeta.
(I ate the chocolate)
In this case, "WA" makes the sentence sounds like "as far as the fact goes, I ate the chocolate." (focus on the fact that whether I ate or not.)
[GA] in general:
Watashi GA sono Chocolate wo Tabeta.
(No one else, but I was the one ate the chocolate)
In this sentence, "GA" emphasis on who ate the chocolate. No one else, but "I" ate it.
It sounds like someone asked "Who ate the chocolate?" and I'm saying "No one else, but I ate the chocolate".
[O] in general:
"O" marks the direct object. In both the sample sentences above, "O" is placed after chocolate (noun), and indicates that chocolate is the direct object.
Now if you'll excuse me, I'm craving some chocolate :) (私[は]チョコレート[を]食べたくなった。Watashi WA chocolate WO Tabetaku natta)