Learn Hardcore Japanese: watasi ha uta ga suki desu.

は is the topic marker. By putting 私 before は, you’re saying “As for me…” It frames 私 (I) as the topic of your statement. The actual grammatical subject of “liking” (好き) is 歌, marked by が.

Why is 歌 followed by が instead of を?

が marks the subject of a predicate adjective like 好き. When you say 歌が好きです, you literally mean “Songs are liked (by me).” If you used を, you’d be trying to treat 好き as a transitive verb, which it isn’t.

What part of speech is 好き, and why do we add です after it?

好き is a na-adjective (形容動詞). Na-adjectives need です (the polite copula) to become a complete polite sentence. So 好きです is the polite form, equivalent to saying “is likable” or “I like (it).”

Why don’t we use a verb like 好む (“to like”) instead of 好き?

You can use 好む in more formal or literary Japanese: 私は歌を好みます. But in everyday conversation, learners almost always use 好き + です because it’s more natural and straightforward.

Can I drop 私は and just say 歌が好きです?

Yes. If the context makes it clear who you’re talking about, you can omit 私は. Japanese often drops pronouns when they’re understood:
• In response to “What do you like?” → 歌が好きです。
• But to introduce your own preference out of the blue, 私は歌が好きです。 is clearer.

Can I drop です and say 歌が好き instead? What’s the difference?

Dropping です gives you the plain form 歌が好きだ (with だ) or just 歌が好き in casual speech.
• 歌が好きです – Polite speech.
• 歌が好きだ – Plain speech (slightly more assertive).
• 歌が好き – Very casual, often in writing or among close friends.

Why is 私が歌が好きです wrong? Can’t I mark 私 with が instead of は?

Using が twice (私が歌が好きです) creates confusion and is ungrammatical here. In 歌が好きです, the first が marks 歌 as the subject of 好き. If you mark 私 with が, you’d have two subjects clashing. Stick with は for the person whose preference you’re stating.

Could I say 歌は好きです instead of 歌が好きです?

Yes, but the nuance shifts.
• 歌が好きです – You’re focusing on your liking for songs; songs are what you like.
• 歌は好きです – You’re comparing songs to something else or contrasting: “As for songs, I like them (but …).” It implies there’s another topic in the background.