kuàidì yǐjīng sòngdào wǒ de bàngōngshì le, wǒ yíhuìr qù qiānshōu.

They often work together, but they do different jobs.

• 已经 marks that something has happened earlier than expected or is already the case.
• 了 marks a new situation or a completed event.

So in 快递已经送到我的办公室了:

• 已经 = the package has already reached the office
• 了 = this is now the current situation

Using both together is very common in Mandarin.
You can think of it as:

• 已经 = emphasizes already
• 了 = signals change/completion

Without 了, the sentence can still work in some contexts, but it may sound less like a newly established situation.

送到 is a verb + result complement structure.

• 送 = to deliver / send / bring
• 到 = to arrive at / reach

Together, 送到 means to deliver something to a destination successfully.

So this pattern focuses not just on the action of delivering, but on the result: the package reached the office.

This kind of structure is very common in Chinese:

• 拿到 = take and obtain / get
• 看到 = look and see
• 写完 = write and finish

So 送到我的办公室 means delivered to my office.

Chinese often does not need an explicit passive marker when the context is clear.

In this sentence, 快递已经送到我的办公室了 naturally means the package has ended up at the office. The focus is on the result, not on who delivered it.

Using 被 is possible in some passive sentences, but here it would usually sound unnecessary.

Compare:

• 快递已经送到我的办公室了 = The package has already been delivered to my office.
• 快递已经被送到我的办公室了 = The package has already been delivered to my office.

The second one is grammatical, but more marked and less natural in ordinary conversation unless you specifically want to highlight the passive idea.

In real-life Mandarin, 快递 can refer to several related things depending on context:

• the express delivery service
• the courier shipment
• the package/parcеl itself

In this sentence, 快递 most naturally means the package.

That kind of noun flexibility is very common in Chinese. Native speakers rely on context more than English often does.

的 marks possession or modification.

• 我 = I / me
• 我的办公室 = my office

In standard Mandarin, 我的办公室 is the normal full form.

Sometimes in casual speech, Chinese can omit 的 in close relationships or very familiar combinations, but with something like 办公室, keeping 的 is the safest and most standard choice.

So:

• 我的办公室 = natural and standard
• 我办公室 = possible in casual speech, but less standard for learners

In this sentence, the 了 at the end of the first clause has scope over the whole clause, not just the last word.

So 快递已经送到我的办公室了 means the situation is now:

• the package has arrived at my office
• this is the new current state

This is often called sentence-final 了, which marks a new state or changed situation.

That is slightly different from a verb-attached 了, though in many cases the distinction overlaps.

Here, 一会儿 means in a little while / shortly / soon.

So 我一会儿去签收 means the speaker plans to go sign for it soon, but not necessarily immediately this second.

Important: 一会儿 can have different meanings depending on context:

• 等一会儿 = wait a moment
• 他一会儿笑，一会儿哭 = one moment he laughs, the next he cries
• 我一会儿去 = I’ll go in a little while

So you must read it from context.

This is because of tone sandhi with 一.

Normally:

• 一 is first tone: yī

But before a fourth-tone syllable, it changes to second tone:

• 会 is fourth tone: huì
• so 一会儿 becomes yí huìr

This is a very common pronunciation rule:

• 一个 → yí ge
• 一次 → yí cì
• 一天 → usually yì tiān? Actually before a first/second/third tone, 一 often becomes fourth tone in connected speech.

So yí huìr is the expected pronunciation here.

签收 means to sign for and receive a delivery.

It is more specific than just 签字:

• 签字 = to sign one’s name
• 签收 = to sign and formally acknowledge receipt of something, especially a package or document

So in the context of delivery, 签收 is exactly the natural word.

Yes, 去 literally means to go, and here it keeps that meaning.

我一会儿去签收 means:

• I’ll go sign for it in a little while

This suggests the speaker will physically go somewhere, such as:

• the front desk
• the mail room
• the reception area
• another office location

Chinese often uses 去 + verb to show going somewhere in order to do something:

• 去吃饭 = go eat
• 去买东西 = go buy things
• 去签收 = go sign for it

Mandarin usually does not mark tense the way English does. Instead, it uses:

• time expressions
• context
• aspect markers
• modal verbs

Here, 一会儿 tells you the action is in the near future.

So 我一会儿去签收 is understood as:

• I’ll go sign for it soon

There is no need for a word equivalent to English will.

It is really doing both, but the emphasis is mostly on the resulting state.

The action happened: the package was delivered.
But the sentence mainly tells you the current situation now:

• the package is at my office

That is one reason why 送到 plus sentence-final 了 sounds so natural here. Chinese often cares very much about the result of an action.

Yes, that is possible, but the nuance is a little different.

• 送到 emphasizes the delivery reaching the office
• 到 emphasizes arrival

So:

• 快递已经送到我的办公室了 = The package has been delivered to my office.
• 快递已经到我的办公室了 or 到了我的办公室了 = The package has arrived at my office.

The original sentence sounds especially natural when talking about delivery logistics.

Measure words are needed in certain structures, especially after numbers or demonstratives:

• 一个快递
• 这个快递
• 两个快递

But when a noun stands alone as the subject/topic, no measure word is needed:

• 快递到了
• 包裹到了
• 人来了

So 快递已经送到我的办公室了 is perfectly normal.

It is natural and fairly neutral. It works well in:

• everyday conversation
• workplace chat
• text messages
• phone calls

A few parts give it a slightly practical, real-world tone:

• 快递
• 办公室
• 签收

So it sounds like normal adult speech, especially in a work context.

Yes, a few things are worth noticing:

• 办 = bàn
• 公 = gōng
• 室 = shì

So: bàngōngshì

Also, in natural speech, the middle and final syllables may flow together quite smoothly, so it can sound faster than learners expect.

And 一会儿 has -r coloring:

• yíhuìr

In some regions, speakers may pronounce the 儿 more strongly or more weakly.

Yes, the object is omitted because it is obvious from context.

我一会儿去签收 naturally means:

• I’ll go sign for the package

Chinese often drops objects when they are already understood. This is very common and very natural.

If you wanted to be more explicit, you could say:

• 我一会儿去签收快递。

But in the original sentence, repeating 快递 is unnecessary.