Self progress report:

[MinusNick]

Konnichi wa. I just want to make sure I am going about learning sentence structure correctly. Would "I like that" be "(Watashi wa) sore ga suki." I'd omit the "watashi wa" if I said something with me as the subject before, right?

[Yudan Taiteki]

It can be omitted whether or not you said something with you as the subject. By default, you are assumed to be the subject. This is especially true of adjectives like "suki", which generally cannot be used with other people without some sort of qualification (i.e. "I think they like it" or "They seem to like it").

[solidsnake360]

I'm also a beginner, but I am pretty sure you would need the copula (だ/です) after すき as well.

[NocturnalOcean]

The copula is not needed.

[chikara]

but です does make the statement more "polite"

[MinusNick]

chikara wrote:
but です does make the statement more "polite"

So if I was talking to a teacher I'd say "Sore ga suki desu," right?
And thanks everyone.

[keatonatron]

MinusNick wrote:

chikara wrote:
but です does make the statement more "polite"

So if I was talking to a teacher I'd say "Sore ga suki desu," right?
And thanks everyone.

Yes, that's right.

NocturnalOcean wrote:
The copula is not needed.

Although the copula can often be dropped, it's a good idea to get into the habit of including it (especially if you're a male).

No sentence will sound strange if you include it.
Many sentences will sound strange if you don't.

[NocturnalOcean]

keatonatron wrote:

NocturnalOcean wrote:
The copula is not needed.

Although the copula can often be dropped, it's a good idea to get into the habit of including it (especially if you're a male).

No sentence will sound strange if you include it.
Many sentences will sound strange if you don't.

That is true. However the poster asked if it was needed. And no it is not needed. To me needed implies 100%. But yeah in many cases it will be needed. And I should rather have given some more information that might not mislead.

[MinusNick]

I thought I had this understood, but a new question popped in my mind:
For "Sore ga suki desu," doesn't "ga" indicate "sore" is the subject? Should "ga" be replaced with "o" or "wo" or a different particle? Due to the fact that in "I like that," "that" is the object.

[solidsnake360]

"ga" marks the object of which you like, so "sore ga suki desu" means "I like that." "o" is only used to mark the object that is being acted on(kuruma o kaimasu, buy a car.) so it would not be appropriate here. Please, anyone correct me if I am wrong.

[Yudan Taiteki]

There are two types of predicates (i.e. verbs, adjectives, and nouns) in Japanese; one type indicates volitional (choice) things and marks the objects with "wo", and the other type indicates non-volitional things and marks the objects with "ga". As far as I know, every noun and adjective falls into the latter category; only verbs can ever take "wo".

Liking something is not something you have control over, so "ga" is used to mark both the subject and the object (although the subject is almost always marked with "wa" instead).

You will see people say that "ga" marks a subject, but when they say this, they do not mean that it marks only things in Japanese that are subjects in English. This is one of the problematic things that you run into when trying to use English grammar to explain Japanese. Using English is usually necessary to explain Japanese grammar, but you should never get too focused on creating one-to-one parallels between English and Japanese.

[keatonatron]

好き is one of the hardest concepts for beginners to understand.

In English, we have the action of "to like", which is something the subject does to an object. In Japanese, the closest equivalent is 好き, which is actually an adjective describing the thing that you like. You can think of 好き as meaning "desireable", "beloved", or what-have-you.

If you keep that in mind, you will see that それが好きです follows the normal AがBです format that adjectives take. それ is the subject in this case, and it is being described as desireable by you, which is why it takes が.

[Yudan Taiteki]

Conflating a grammatical category with a meaning category doesn't seem like the best way to go -- direct objects in English are not always things that the subject is doing something to (i.e. "I understand Japanese", "I like fish", "I feel good"). Likewise, "ga" marked nouns in Japanese are not always subjects.

彼がすしが好きだから、すし屋に行った方がいいと思う。 How do you explain that first clause if "sushi" is the subject? What's "kare" then?