jigeumeun gongwoni aju joyonghaeyo.

They do different jobs.

• 은/는 marks the topic
• 이/가 marks the subject

So in 지금은 공원이 아주 조용해요:

• 지금은 = as for now / right now
• 공원이 = the park is the thing being described as quiet

A natural way to think about it is:

• 지금은 sets the time frame
• 공원이 is the thing that is quiet

So the sentence is not just Now, the park is very quiet, but more like:

• As for now, the park is very quiet.

This combination of a topic and a subject is very common in Korean.

Adding 은 gives 지금 a topic or contrastive feeling.

• 지금 = now
• 지금은 = as for now / at least for now / right now

So 지금은 can suggest a contrast with another time, even if that contrast is only implied.

For example, it can feel like:

• Right now, the park is very quiet.
  (Maybe earlier it was noisy, or later it may not be quiet.)

If you say just 지금 공원이 아주 조용해요, that is also understandable, but 지금은 sounds more natural when you want to frame the statement around the present moment.

공원이 marks 공원 as the subject of the sentence: the park is the thing that is quiet.

• 공원이 아주 조용해요 = The park is very quiet

If you said 공원은 아주 조용해요, that would make the park the topic instead. That is also grammatical, but the nuance changes a bit.

Compare:

• 공원이 아주 조용해요
  = The park is very quiet
  (Focus on the park as the subject)

• 공원은 아주 조용해요
  = As for the park, it is very quiet
  (Topic-oriented, possibly contrasting it with something else)

In your sentence, 지금은 is already the topic, so 공원이 works well as the subject inside that time frame.

In Korean grammar, 조용하다 is usually treated as a descriptive verb. In English, we often translate it like an adjective: quiet.

So:

• 조용하다 = to be quiet
• 조용해요 = is quiet / are quiet

This is why Korean does not need a separate word like is in English.

English:

• The park is quiet

Korean:

• 공원이 조용해요

The Korean predicate already contains the idea of being quiet, so no extra to be verb is needed.

This is because 조용하다 is a 하다-type word.

Many Korean words ending in 하다 change like this in the polite present form:

• 하다 → 해요
• 조용하다 → 조용해요

So the pattern is:

• dictionary form: 조용하다
• polite present: 조용해요

Other examples:

• 필요하다 → 필요해요
• 편하다 → 편해요

So 조용해요 is just the normal polite present-tense form.

아주 means very.

So:

• 아주 조용해요 = very quiet

It is a straightforward degree adverb.

Some similar words:

• 아주 = very
• 정말 = really
• 너무 = too / very, depending on context

Examples:

• 아주 조용해요 = very quiet
• 정말 조용해요 = really quiet
• 너무 조용해요 = too quiet / very quiet

A note about 너무: in modern conversation, people often use it casually to mean very, but originally it has more of a too much feeling. For a learner, 아주 is a safe and clear choice for very.

Korean usually puts the predicate at the end.

English:

• The park is very quiet now.

Korean:

• 지금은 공원이 아주 조용해요.
• literally: As for now, the park very quiet-is

A simple breakdown is:

• 지금은 = time/topic
• 공원이 = subject
• 아주 = adverb
• 조용해요 = predicate

Korean is often described as an SOV language, but with descriptive verbs like this, it can be helpful to think:

• everything comes first
• the main descriptive word comes last

That final position is one of the most important habits to get used to in Korean.

Yes, if the context already makes it clear what you are talking about.

For example, if you are already discussing the park, you could say:

• 지금은 아주 조용해요.

That would mean something like:

• It’s very quiet now.
• Right now, it’s very quiet.

Korean often omits subjects when they are understood from context. But in your full sentence, 공원이 is included to make it explicit that the park is what is quiet.

조용해요 is the polite informal style, often called the 해요 style.

It is very common in everyday conversation and is appropriate in many situations.

Compare:

• 조용해 = casual, plain informal
• 조용해요 = polite everyday speech
• 조용합니다 = more formal

So your sentence is polite and natural for normal conversation:

• 지금은 공원이 아주 조용해요.

If you wanted a more formal version, you could say:

• 지금은 공원이 아주 조용합니다.

Yes, there can be, especially because of 지금은.

Using 은 often creates a feeling of contrast, even if it is subtle. So the sentence may imply something like:

• Right now, the park is very quiet
  (but maybe at other times it is noisy)

The speaker does not have to say the contrast out loud. Korean often leaves that implied.

So depending on context, this sentence can feel like:

• It’s quiet now
• At the moment, it’s quiet
• For now, the park is very quiet

That contrastive nuance is one reason 지금은 sounds natural here.

Here are some useful variations:

• 지금은 공원이 아주 조용해요.
  = polite present

• 지금은 공원이 아주 조용합니다.
  = more formal present

• 지금은 공원이 아주 조용해.
  = casual present

• 아까는 공원이 아주 조용했어요.
  = The park was very quiet earlier.

• 지금은 공원이 별로 조용하지 않아요.
  = The park isn’t very quiet now.

These are helpful because they show that the core predicate is 조용하다, which changes by tense and speech level just like other Korean predicates.