Particles, and "ii yo ne"

[Rockuman]

There's a few particles I'm a little lost on. I'm hoping someone can clear it up for me.

Kore da
Kore de
Watashi wa & Watashi ga (not sure what the difference is)

And also, I often hear that "ii yo ne" can be translated as "Be prepared" or something similar. I'm not sure how "Good, an emphasis particle, and an agreement" come together to form preparation, but, that's what I'm here for. :)

[Glenn]

Kore da

This one isn't a particle. It's the copula. It's best thought of in English as the verb "to be," but perhaps more accurately it can be thought of as an equal sign. Kore da -> "It's this."

Kore de

De is used to show an instrument (basu de ikimashita -> "I went by bus") or location of some action (kouen de asonda -> "We played in the park."). It also has some uses that seem to be an extension of this. Kore de seems to be most often translated as "now," but it's more like "by means of this." Here's an example: Kore de daigaku ni ikeru -> "Now I will be able to go to college/university." Note here that literally this is more like "by means of this I can go to college," where "this" is something understood from context, like getting a grant, for instance.

Watashi wa & Watashi ga (not sure what the difference is)

Most people have problems with this. For this problem I will refer you to this page about topics and focuses (www.sf.airnet.ne.jp/~ts/japanese/topicfocus.html).

And also, I often hear that "ii yo ne" can be translated as "Be prepared" or something similar. I'm not sure how "Good, an emphasis particle, and an agreement" come together to form preparation, but, that's what I'm here for. :)

Check out the EXCEED和英辞典 (http://dictionary.goo.ne.jp/search.php?MT=%A4%A4%A4%A4&kind=je&mode=0&base=1&row=1) definition of ii. It can mean "alright" or "enough," as well as "good." I think in the situation you're talking about there is probably an understood subject (perhaps more accurately, an unstated topic), kakugo. The phrase kakugo wa ii means to be prepared for some bad fate. Saying ii yo ne is probably like saying "you're prepared for your fate, aren't you?" I'm not sure I did a good job with that one. We'll find out when some of the more knowledgeable members stop by.

[Scrivener]

"ii" means good, but it can have a nuance of giving permission. "ii yo ne" in that context sounds like (probably a girl) asking for permission to do something. It's like "you don't mind if we start, now, do you?" which could be translated as "be prepared" in some circumstances.