kono seito ha yuusyuu desu.

It is read:

この せいと は ゆうしゅう です。

In rōmaji:

Kono seito wa yūshū desu.

A few pronunciation notes:

• は is written ha but here it is pronounced wa because it is the topic particle.
• です is often pronounced softly, and the u may be barely audible in natural speech.

The spaces are usually just for learners.

In normal Japanese writing, this would usually be written as:

この生徒は優秀です。

Japanese does not normally use spaces between words the way English does. Textbooks and beginner materials often add spaces to make the structure easier to see.

この means this, and it must be followed by a noun.

So:

• この 生徒 = this student

A useful comparison:

• この + noun = this _
• その + noun = that _ near the listener
• あの + noun = that _ over there

Also, この cannot stand by itself. You can say:

• この生徒 = this student

But not just この to mean this one. For this one, Japanese uses これ.

Because この directly modifies a noun by itself.

So you say:

• この生徒 = this student

not:

• このの生徒 ✗

Words like この, その, and あの already function as determiner-type words, so they do not need の.

生徒 means student, but it often refers to a student in a school setting such as elementary school, middle school, or high school.

It is not always exactly the same as 学生:

• 生徒: pupil/student, often school student
• 学生: student, often used for college or university students, though it can also be broader in some contexts

So この生徒は優秀です sounds like This student/pupil is excellent, often in a teacher-or-school context.

は marks the topic of the sentence.

So:

• この生徒は = as for this student...

Then the rest of the sentence says something about that topic:

• 優秀です = is excellent

A natural way to understand the structure is:

• As for this student, [they] are excellent.

In English, we usually just say This student is excellent, but Japanese often organizes sentences as topic + comment.

This is a special case for the particle は.

When は is used as a topic particle, it is pronounced wa:

• この生徒は → kono seito wa

But when は is part of a regular word, it is usually pronounced ha.

This is just one of those important spelling-and-pronunciation conventions you memorize early in Japanese.

優秀 is what is often called a na-adjective in beginner textbooks, though grammatically it behaves more like a noun-like descriptive word.

It means something like:

• excellent
• outstanding
• superior

Unlike an i-adjective, it does not end in -い. That is why it does not become 優秀い or anything like that.

Before a noun, it uses な:

• 優秀な生徒 = an excellent student

At the end of a polite sentence, it can be followed by です:

• この生徒は優秀です = This student is excellent.

Because 優秀 is not an i-adjective.

With an i-adjective, you can say:

• この生徒はすごいです
• この生徒は賢いです

But with a na-adjective like 優秀, you say:

• この生徒は優秀です

In polite speech, です gives the sentence a polite ending. In plain style, you could say:

• この生徒は優秀だ
• この生徒は優秀

The second one is more casual and context-dependent.

Japanese sentence structure works differently from English.

English needs a linking verb:

• This student is excellent.

Japanese does not place a separate word in the middle in the same way. Instead, the sentence ends with です here:

• この生徒は優秀です

So Japanese often puts the main predicate at the end of the sentence. That is very normal.

The structure is:

この生徒 + は + 優秀です

or:

this student + topic marker + is excellent

Japanese often follows a topic/comment pattern, and the predicate comes at the end.

So rather than thinking only in terms of English word order, it helps to see it as:

• Topic: this student
• Comment: is excellent

Yes, but it changes the nuance.

• この生徒は優秀です: As for this student, they are excellent.
• この生徒が優秀です: This student is the excellent one / It is this student who is excellent.

Very roughly:

• は presents a topic
• が can mark the subject more directly and often sounds more specific, contrastive, or identifying depending on context

If you are just making a general statement about the student, は is the most natural choice.

Yes. It is in polite style because it ends with です.

Polite:

• この生徒は優秀です。

Plain:

• この生徒は優秀だ。
• この生徒は優秀。 ← casual, often used in conversation

So the original sentence is appropriate in normal polite conversation, classroom discussion, or formal everyday situations.

You would put な after 優秀 because it modifies a noun:

• 優秀な生徒 = an excellent student

This is a very important pattern for na-adjectives:

• 静かな部屋 = a quiet room
• 有名な人 = a famous person
• 優秀な生徒 = an excellent student

So:

• この生徒は優秀です = This student is excellent.
• この生徒は優秀な生徒です = This student is an excellent student.

The second version is grammatical, but it sounds more repetitive than necessary.

Not exactly.

優秀 is stronger and more specific than just good. It suggests someone is excellent, outstanding, or high-performing.

For example, it often implies ability, performance, or quality in a noticeable way.

So this sentence sounds more like:

• This student is excellent
• This student is outstanding

rather than just:

• This student is good

That makes 優秀 a useful word in academic, professional, or evaluative contexts.