Learn Hardcore Japanese: watasi ha koohii ni gyuunyuu wo sosogimasu.

In Japanese は (wa) is the topic marker. It tells the listener “as for me…,” framing 私 as the topic of the conversation. By contrast, が (ga) is the subject marker, often used to introduce new information or to emphasize who is performing the action. Since you’re simply stating what you do (not emphasizing “I” over someone else), 私は is the natural choice here.

What role does に play after コーヒー?

Here に marks the target or destination of the pouring—“into the coffee.” In Japanese, when you “pour” something into a receptacle, you mark that receptacle with に.

Why is を used after 牛乳 instead of が?

The particle を (o) marks the direct object of the verb—in this case, 牛乳 (milk) is what you are pouring. が could technically mark the subject in some constructions, but here you need を to show that milk is the item being acted upon.

Why is the verb 注ぎます in the -ます form? What’s its dictionary form?

注ぎます is the polite present/future form of the verb. The dictionary (plain) form is 注ぐ (そそぐ).
– 注ぐ → plain/dictionary form (“to pour”)
– 注ぎます → polite present/future (“I pour” / “I will pour”)

Can I swap the objects, saying 牛乳をコーヒーに注ぎます instead?

Yes. Because of particles, the sentence remains grammatical and clear. Japanese word order is flexible as long as particles mark each element correctly. However, the most common natural flow is コーヒーに牛乳を注ぎます (IO → DO → V), but 牛乳をコーヒーに注ぎます (DO → IO → V) is also acceptable.

Do I have to include 私は, or can I omit it?

You can omit 私は if the context makes it obvious who is doing the action. Japanese often drops pronouns when they’re clear from context. So in a coffee-making context you’ll frequently hear just コーヒーに牛乳を注ぎます.

Why are there spaces between the words in this sentence? I thought Japanese doesn’t use spaces.

Native Japanese writing typically doesn’t use spaces. They’ve been added here for teaching purposes—to help you see each particle and word boundary clearly. In real text you’d write it as 私はコーヒーに牛乳を注ぎます。

What’s the difference between 注ぎます and 入れます, since both can mean “put into”?

注ぐ (そそぐ) specifically means “to pour” a liquid, emphasizing the act of pouring. 入れる (いれる) is more general “to put in” or “insert,” applicable to liquids or solids. So with liquids like milk you’ll usually hear 注ぐ, whereas 入れる is fine but less precise (“put milk into coffee”).

Could I use へ instead of に after コーヒー?

No—へ indicates movement toward a location (“toward coffee”), but not entering into it. For pouring something into a container, you need に to mark the destination inside the receptacle.

Why is コーヒー written with a long dash (ー)?

That dash (ー) is the Chōonpu, the Katakana long-vowel mark. It indicates that the vowel is held longer. So コーヒー is pronounced kōhī (long “o” and long “i”), matching the English “coffee.”