oneureun barami ganghaeseo changmuneul dadayo.

-은/는 is the topic marker. In 오늘은, it means as for today or today, regarding the situation.

So 오늘은 바람이 강해서 창문을 닫아요 has a natural feeling like:

• As for today, the wind is strong, so I’m closing the window.
• Today, because it’s windy, I close the window.

The topic marker often sets the scene or contrasts with other times. For example, it can imply something like today in particular.

Here 바람이 uses the subject marker -이/가 because 바람 is the thing being described by 강하다.

• 바람이 강하다 = The wind is strong

A simple way to think about it:

• 은/는 = topic, background, contrast
• 이/가 = subject, the thing that actually has the property or does the action

In this sentence:

• 오늘은 = sets the topic: today
• 바람이 강해서 = says what is true: the wind is strong
• 창문을 닫아요 = main action: (someone) closes the window

So the combination of 오늘은 and 바람이 is very natural.

강해서 comes from the adjective 강하다, which means to be strong.

It is formed like this:

• 강하다
• stem: 강하-
• -아서/어서 form: 강해서

Here -아서/어서 means because or links one clause to the next.

So:

• 바람이 강해서 = because the wind is strong / the wind is strong, so...

This form is extremely common in Korean for showing cause and effect.

In Korean, -아서/어서 is one of the most natural everyday ways to say because.

So instead of saying something like:

• Because the wind is strong, ...

Korean often says:

• 바람이 강해서 ...
• literally: the wind being strong, ...

It sounds smooth and conversational. It is very common in speech.

A rough comparison:

• 바람이 강해서 창문을 닫아요 = natural everyday Korean
• 바람이 강하니까 창문을 닫아요 = also natural, with a slightly different feel
• 바람이 강하기 때문에 창문을 닫아요 = more formal/written, like because of the fact that...

In this sentence, it means because it is strong or so, since it is strong.

Technically, -아서/어서 can sometimes simply connect actions or descriptions in sequence, but with a sentence like this, the meaning is clearly cause and result:

• 바람이 강해서 = because the wind is strong
• 창문을 닫아요 = (I) close the window

So the whole sentence means that the strong wind is the reason for closing the window.

-을/를 is the object marker. It marks the thing that the action is done to.

• 창문 = window
• 창문을 닫아요 = close the window

So here:

• 닫다 = to close
• 창문을 닫다 = to close the window

This is the standard way to mark the direct object in Korean.

닫아요 is the polite present-style form of 닫다.

It changes like this:

• dictionary form: 닫다
• stem: 닫-
• polite ending: -아요/어요
• result: 닫아요

This is a regular polite conversational form.

So:

• 닫다 = to close
• 닫아요 = close / am closing / close it

Depending on context, Korean present tense can sound like:

• I close
• I’m closing
• I will close

In this sentence, I’m closing the window or I close the window both fit.

Korean often leaves out the subject when it is understood from context.

So 창문을 닫아요 does not explicitly say:

• I close the window
• we close the window
• someone closes the window

But in normal conversation, listeners usually understand the subject from the situation. In many contexts, it would naturally mean:

• I’m closing the window
• We’re closing the window

This is very common in Korean. Pronouns like 저, 나, 우리 are often omitted unless they are needed for emphasis or clarity.

Korean present tense is broader than English present tense. It often covers meanings that English expresses with:

• I close
• I’m closing
• I will close

So 창문을 닫아요 can mean:

• I close the window
• I’m closing the window
• I’ll close the window

In this sentence, the most natural English translation is often I’m closing the window because it’s windy today, even though Korean uses the present polite form.

Context decides the best English wording.

Yes, 강하다 can be used for wind and means strong.

But learners should know that 세다 is also very common for things like wind, rain, pressure, smell, flavor, and force.

So both can appear in real Korean:

• 바람이 강해요 = the wind is strong
• 바람이 세요 = the wind is strong

In everyday speech, 바람이 세요 is often very common. 강하다 is still perfectly understandable and natural.

Yes. The topic marker -은/는 often adds a slight contrastive nuance.

So 오늘은 can simply mean today, but depending on context it may also suggest:

• today, unlike other days
• at least today
• today in particular

For example, if yesterday the weather was calm, 오늘은 바람이 강해서... might imply but today the wind is strong.

This contrast is often subtle and depends on context and intonation.

Korean word order is somewhat flexible, but this sentence is in a very natural standard order:

• 오늘은 = topic/time
• 바람이 강해서 = reason
• 창문을 닫아요 = main action

You may see variations, but the verb normally comes at the end. For example:

• 바람이 강해서 오늘은 창문을 닫아요

This is also possible, but it gives a slightly different emphasis. The original sentence is straightforward and very natural for learners to model.

닫아요 is in the polite informal style, often called the -아요/어요 style.

It is polite and commonly used in everyday conversation with:

• strangers
• coworkers
• teachers
• people you are not close to

It is less formal than 닫습니다, but more polite than plain casual forms like 닫아.

So:

• 닫아 = casual
• 닫아요 = polite everyday
• 닫습니다 = formal

The sentence sounds polite and natural for normal conversation.