Learn Hardcore Japanese: watasi ha tomodati to issyo ni nihon no ryouri wo tabetai desu. - I want to eat Japanese cuisine together with my friend.

If you used が instead (私が友達と…), it would sound like you are emphasizing I (not somebody else) as the one who wants to eat, often in contrast to others.
For a neutral “I want to…”, 私は is more natural in isolation or in everyday conversation.

Why isn’t there a particle after 友達? Shouldn’t it be 友達を or 友達に?

The particle for 友達 is actually there: it’s と.

友達と is one set phrase: friend + と (“with my friend(s)”).

So 友達 doesn’t need an extra particle like を or に. The chunk is:

友達と一緒に = “together with (my) friend(s)”

What does the particle と do in 友達と? Isn’t と usually “and”?

と has two very common uses:

To link nouns as “and”
- りんごとバナナ = apples and bananas
To mark a companion, meaning “with”
- 友達と行く = go with a friend

In 友達と一緒に, と is the “with” usage.
So 友達と means “with (my) friend(s)”, not “friend and …” here.

What is the role of 一緒に? Could I just say 友達と日本の料理を食べたいです?

一緒に literally means “together” and emphasizes doing the action together with someone.

友達と日本の料理を食べたいです。
→ “I want to eat Japanese food with my friend(s).” (natural)
友達と一緒に日本の料理を食べたいです。
→ “I want to eat Japanese food together with my friend(s).” (adds emphasis on togetherness)

In many cases, 友達と already implies “together”, so 一緒に is optional. Adding it just makes the “together” nuance stronger or clearer.

Why is there a に after 一緒? What does 一緒に function as?

一緒に is a set phrase:

一緒 (いっしょ) = together
に = adverb-forming particle here

一緒に works as an adverb meaning “together”:

一緒に行く = go together
一緒に食べる = eat together

You don’t treat 一緒 and に separately in this sentence; just remember 一緒に as “together (with someone)”.

What is the difference between 日本の料理 and 日本料理?

Both can mean “Japanese food / Japanese cuisine”, but there’s a nuance:

日本の料理
- Literally: “the cooking/food of Japan”
- Very common, neutral, and easy for learners.
日本料理 (にほんりょうり)
- A more compact noun meaning “Japanese cuisine”
- Feels a bit more formal or “category-like” (like “Italian cuisine” vs “Italian food”).

In everyday conversation, 日本の料理 is perfectly natural and often a bit more beginner-friendly.
You could also say:

日本料理を食べたいです。 (also correct and natural)

How is 日本の料理 different from 和食?

Both usually translate as “Japanese food”, but:

日本の料理
- Literally “the cuisine/food of Japan”
- Broad and descriptive, what you see in the example sentence.
和食 (わしょく)
- Specifically “Japanese-style food”, often in contrast to 洋食 (Western-style food).
- Stronger cultural nuance; can sound a bit more like “traditional Japanese food”.

Your sentence would still be natural as:

和食を友達と一緒に食べたいです。
→ “I want to eat Japanese (style) food with my friend(s).”

Why do we use を before 食べたい? What is 料理を doing?

を marks the direct object of the verb:

料理を食べる = eat food
本を読む = read a book
水を飲む = drink water

In your sentence:

日本の料理を食べたい
→ “(I) want to eat Japanese food.”

So 料理 is what is being eaten, and を tells us it’s the thing directly acted on by the verb.

Why is it 食べたいです instead of just 食べたい? What’s the difference?

Both are grammatically correct:

食べたい。
- Casual/plain form
- Used with friends, family, or people you’re close to.
食べたいです。
- Polite form
- Appropriate with strangers, teachers, in shops, with superiors, etc.

です doesn’t change the basic meaning; it just adds politeness to the sentence.
So:

日本の料理を食べたいです。
→ Polite “I want to eat Japanese food.”

Why does the sentence end with です even though 食べたい already looks like a verb form?

In Japanese, ～たい is actually treated as an -i adjective (like 大きい, 高い), even though it comes from a verb.

So grammatically, 食べたい works similarly to an adjective:

食べたい = “(I) want to eat”
食べたくない = “don’t want to eat”

In polite speech, -i adjectives can be followed by です to sound polite:

楽しいです。 = It’s fun.
忙しいです。 = I’m busy.
食べたいです。 = I want to eat.

So です is there for politeness, not because 食べたい needs a “copula” in a strict grammatical sense.

Can I leave out 私 in this sentence?

Yes, and it’s very common to do so:

友達と一緒に日本の料理を食べたいです。

Japanese often omits the subject (I, you, he, etc.) when it’s clear from context.
If you’re talking about your own plans/desires, people will naturally understand “I” even if you don’t say 私.

Is 友達 singular or plural? Does it mean “a friend” or “friends”?

友達 (ともだち) by itself does not mark singular or plural. It can mean:

“a friend”
“my friend”
“friends”
“my friends”

The number is usually clear from context.
If you really need to be explicit, you can say:

一人の友達 = one friend
二人の友達 = two friends
何人かの友達 = some friends

But in everyday conversation, 友達と一緒に食べたい is fine, and context will decide whether it’s one or more friends.

Can the word order be changed, like putting 一緒に somewhere else?

Japanese word order is somewhat flexible, but the verb must come last.
Your sentence:

私は / 友達と / 一緒に / 日本の料理を / 食べたいです。

Common, natural variations include:

私は日本の料理を友達と一緒に食べたいです。
友達と一緒に日本の料理を食べたいです。 (dropping 私)

You wouldn’t normally separate 友達と and 一緒に far apart, because they function together as “together with (friends)”. So something like:

✕ 友達と日本の料理を一緒に食べたいです。

is still understandable and sometimes used, but 友達と一緒に日本の料理を食べたいです is smoother and more standard.

How would I say “I want to eat Japanese food with my Japanese friend” using this pattern?

You just specify that the friend is Japanese using 日本人の友達:

私は日本人の友達と一緒に日本の料理を食べたいです。
→ “I want to eat Japanese food together with my Japanese friend.”

Breakdown:

日本人の友達 = (my) Japanese friend
日本の料理 = Japanese food/cuisine

How would I say “I want to eat and drink Japanese food and (Japanese) tea with my friend” keeping the same style?

You can connect verbs with て-form and list objects with と:

私は友達と一緒に日本の料理を食べて、日本のお茶を飲みたいです。

Meaning: “I want to eat Japanese food and drink Japanese tea together with my friend.”

Structure:

日本の料理を食べて = eat Japanese food and then / and …
日本のお茶を飲みたいです = want to drink Japanese tea.