"I do not like the subway."
Isn't either correct? I didn't think using が vs は depended on the words used, but the context. I thought one would use が for statements like this when the statement is something new to the conversation or if the speaker wanted to place more emphasis on the action whereas using は makes the sentence a basic statement with no real emphasis.
In this case, yes. You would use wa if the sentence was longer and you wanted to emphasize something else, such as the reason you don't like the subway.
For example: 地下鉄は好きじゃなくて、ネズミがいっぱいですよ (I don't like the subway, it's full of rats)。
Here, the ga in the second half implies more emphasis and fits the grammar.
ネズミ is commonly writtrn in katakana, like ゴミ, シワ.
でいっぱい is "filled with" or "covered with" e.g. 水でいっぱい filled with water. がいっぱい means there is a lot. So ネズミでいっぱい is like the compartment is stuffed with rats, that would be nasty :-)
(The first usage vs the second usage from weblio)
容器・建物・場所などに入る限界にまで達しているさま。 「水が－たまる」 「会場は人で－だ」
非常にたくさんであるさま。 「元気－働く」 「客が－きた」
A 日本人 friend told me that it's common to write certain animals in katakana rather than hiragana or even kanji. She said that this is common for kanji that is difficult/complicated to write - the katakana is just faster and easier. She also confirmed that ネズミが いっぱい です is correct or used over ネズミで. Happy to learn from my mistakes : )
It does answer your question - すき is not an 'i' adjective therefore it needs です. 'i' adjectives conjugate or their endings inflect (change) to show negative, positive, past, present etc like verb endings - 好き is not an 'i' adjective so です does all of that for it. 好きです - I like , 好き では ありません - I don't like etc
To fill the gap between your answer and Britt1110's concern -
好き では ありません is the formal negative form of a な-adjective.
Now では's oral form is じゃ and ありません = ないです. ない is い-adjective and there are two polite forms e.g. たかい -> たかく ありません or たかく ないです
好きだ is a correct positive ordinary form, while 好きじゃない is a correct negative ordinary form, and 好きじゃないです and 好きじゃありません are two correct negative polite forms.