balsongini mulgeoneul eoje balsonghaessseupnida.

발송인 means sender or shipper. It is a noun:

• 발송 = dispatch / sending
• 인 = person

So 발송인 literally means the person who sends something.

The -이 is the subject marker. It shows that 발송인 is the subject of the sentence:

• 발송인이 = the sender (as the subject)

In this sentence, the sender is the person doing the action of sending.

-을/를 is the object marker in Korean. It marks the thing that receives the action.

Here:

• 물건 = item / object / goods
• 물건을 = the item (as the object)

So the sentence structure is basically:

• 발송인이 = the sender (subject)
• 물건을 = the item (object)
• 어제 발송했습니다 = sent yesterday

In other words, the sender sent the item yesterday.

Yes. 어제 means yesterday, and time expressions in Korean are often placed before the verb, but they are fairly flexible.

So these are all possible:

• 발송인이 물건을 어제 발송했습니다.
• 발송인이 어제 물건을 발송했습니다.
• 어제 발송인이 물건을 발송했습니다.

All are grammatically possible, but the emphasis can feel slightly different depending on placement.

A very common neutral order is:

• 발송인이 어제 물건을 발송했습니다.

Korean word order is more flexible than English because particles like -이 and -을 show each word’s role.

That is a great thing to notice. Yes, both are based on 발송:

• 발송인 = sender
• 발송했습니다 = sent / dispatched

So the sentence has a somewhat repetitive, technical feel, like:

• The sender dispatched the item yesterday.

This is not wrong, but it sounds formal and a little stiff. In everyday Korean, people often prefer 보내다 instead:

• 보내는 사람이 어제 물건을 보냈어요.
• 판매자가 어제 물건을 보냈어요.

So your original sentence is grammatically correct, but it sounds more like written, logistical, or system-style Korean.

발송했습니다 is a formal polite past-tense verb form.

It breaks down like this:

• 발송하다 = to dispatch / to send
• 발송했- = sent / dispatched (past stem)
• -습니다 = formal polite ending

So 발송했습니다 means:

• sent
• dispatched
• has sent (depending on context in English)

This style is commonly used in:

• announcements
• business language
• official writing
• customer service
• formal speech

Korean past tense does not map perfectly onto English tense choices.

발송했습니다 can often be translated as:

• sent
• has sent

The best English translation depends on context.

For example:

• If you are simply describing a completed action in the past: sent
• If you are reporting a completed shipping action that matters now: has sent

Korean itself is mainly telling you that the action was completed in the past. The exact English tense depends on how natural it sounds in the situation.

Korean does not have articles like a, an, or the.

So 발송인 can mean:

• a sender
• the sender

And 물건 can mean:

• an item
• the item
• goods

You figure out the exact meaning from context.

That is very normal in Korean. Learners often want every noun to be clearly marked as a or the, but Korean usually leaves that unstated.

물건 is correct and understandable, but it is a bit general. It means thing, item, or goods.

Depending on context, other words may sound more natural:

• 상품 = product / merchandise
• 소포 = package / parcel
• 택배 = delivery package / courier parcel

For example:

• 발송인이 상품을 어제 발송했습니다.
• 판매자가 어제 상품을 발송했습니다.
• 어제 택배를 보냈어요.

So 물건 is fine, but it is broad and generic.

Usually not in casual everyday conversation. It sounds grammatical, but somewhat formal and administrative.

A native speaker might say something more natural like:

• 보내는 사람이 어제 물건을 보냈어요.
• 판매자가 어제 물건을 보냈어요.
• 어제 발송했어요.
• 어제 보냈어요.

Your original sentence sounds more like:

• a shipping notice
• a logistics record
• a formal report
• a system message

So it is good Korean, but not the most casual or conversational phrasing.

Yes, depending on what you want to emphasize.

Compare:

• 발송인이 물건을 어제 발송했습니다.
• 발송인은 물건을 어제 발송했습니다.

The version with -이/가 focuses more on who did it or presents the subject more neutrally.

The version with -은/는 gives more of a topic feeling, like:

• As for the sender, they sent the item yesterday
• or a contrastive feeling, depending on context

For a simple standalone sentence, -이 is perfectly fine. But -은/는 could also be used if the discourse context supports it.

The structure is:

• 발송인이 = subject
• 물건을 = object
• 어제 = time expression
• 발송했습니다 = verb

So the pattern is basically:

Subject + Object + Time + Verb

A very common Korean sentence pattern is:

Subject + Object + Adverb/Time + Verb

Since Korean is a verb-final language, the verb usually comes at the end.

That is one of the biggest differences from English.