geu seonsaengnimeun ajik jeolmseupnida.

In this sentence, 그 means that (as in that teacher) or sometimes the, depending on context.

So 그 선생님은 is that teacher / the teacher.

A common beginner confusion is that 그 can also mean he in some textbook-style Korean, but in real everyday Korean, it more often works like that when it comes before a noun.

• 그 사람 = that person / he
• 그 선생님 = that teacher

Here, because it directly modifies 선생님, it clearly means that teacher.

은 is the topic particle. It marks 선생님 as the topic of the sentence.

So 그 선생님은 아직 젊습니다 is something like:

• As for that teacher, he/she is still young.

Using 은/는 often gives a topic or contrast nuance, while 이/가 more strongly marks the grammatical subject or introduces new information.

In many situations, both can be possible, but they feel slightly different:

• 그 선생님은 아직 젊습니다.
  = As for that teacher, he/she is still young.
• 그 선생님이 아직 젊습니다.
  = That teacher is still young. / It is that teacher who is still young.

For a basic descriptive statement, 은/는 is very natural.

선생님 is the normal respectful word for teacher in Korean.

It contains 님, an honorific element that adds respect. Since teachers are usually spoken about respectfully, 선생님 is the standard choice.

A learner might wonder whether 선생 is enough, but on its own it is much less common in everyday modern Korean when referring to a teacher politely. 선생님 is the natural form.

It can also be used for other respected professionals in some contexts, but here it simply means teacher.

아직 means still or yet, depending on the sentence.

In this sentence, it means still:

• 아직 젊습니다 = is still young

It suggests that the teacher remains young, perhaps compared to what might be expected.

A useful pattern:

• 아직 + positive statement = still
  
  • 아직 젊어요. = Still young.
• 아직 + negative statement = not yet
  
  • 아직 안 왔어요. = Hasn’t come yet.

So here, because the sentence is positive, 아직 is best understood as still.

젊습니다 is the formal polite present form of the adjective 젊다, which means to be young.

Breakdown:

• Dictionary form: 젊다
• Formal polite present: 젊습니다

This style is often used in:

• speeches
• presentations
• news
• formal writing
• polite public situations

A less formal polite version would be:

• 젊어요

So:

• 그 선생님은 아직 젊습니다. = formal polite
• 그 선생님은 아직 젊어요. = everyday polite

Because 젊다 already means to be young.

In Korean, many descriptive words are often called adjectives in English-learning materials, but grammatically they behave more like descriptive verbs. That means they can be conjugated directly without adding a separate verb like is.

So English:

• The teacher is young

Korean:

• 선생님은 젊습니다
• literally closer to: Teacher-topic young-is

But in Korean, 젊습니다 already contains the meaning of is young.

The sentence follows a very common Korean pattern:

topic + adverb + predicate

So:

• 그 선생님은 = that teacher + topic marker
• 아직 = still
• 젊습니다 = is young

Korean usually puts the main verb or adjective at the end of the sentence.

So the structure is:

• 그 선생님은 / 아직 / 젊습니다
• As for that teacher / still / is young

This is why Korean word order often feels reversed compared with English.

Yes, very often.

If the context already makes it clear which teacher you mean, Korean often drops words that English would keep. So you could simply say:

• 선생님은 아직 젊습니다.

This would mean:

• The teacher is still young
• or As for the teacher, he/she is still young

Korean frequently relies on context, so omitting 그 is very natural when the listener already knows which teacher is being discussed.

Yes. It sounds polite and respectful.

There are two main reasons:

1. 선생님 is a respectful word for teacher.
2. 젊습니다 is in the formal polite style.

So this sentence would be appropriate in formal conversation or when speaking respectfully about a teacher.

If you were speaking casually with friends, you might say:

• 그 선생님은 아직 젊어요.

That is still polite, just less formal than 젊습니다.

Yes, it can, depending on context.

Because 은 can sometimes create a contrastive nuance, 그 선생님은 아직 젊습니다 might subtly suggest something like:

• That teacher, at least, is still young
• That teacher is still young (though others may not be)

However, this contrast is not always strong. In many cases, it is just a normal topic marker with no major contrast intended.

Context and intonation decide how strong that contrast feels.

Usually yes in a positive sentence like this, but not always word-for-word.

Here, still young is the most natural translation. But Korean adverbs do not always match English adverbs perfectly in every context.

For this sentence, the important idea is:

• the teacher continues to be young
• the state has not changed yet

So still young is the best natural English rendering here.