wǒ yǐjīng zài wǎngzhàn shàng xiàdān le, kuàidì míngtiān huì sòngdào wǒ jiā.

They often work together, but they do different jobs.

• 已经 means already
• 了 here marks a new situation or completed action

So 我已经……了 is a very common pattern meaning I have already...

In this sentence, 我已经在网站上下单了 means I’ve already placed the order on the website.

You can sometimes omit one of them if the context is clear, but using both is very natural.

在 introduces a location, and 上 is a localizer meaning something like on.

So:

• 网站 = website
• 网站上 = on the website
• 在网站上 = on the website

Chinese often uses these localizers after nouns of place:

• 在桌子上 = on the table
• 在墙上 = on the wall
• 在线上 = online

So 在网站上 is the natural way to say on the website.

下单 is a fixed expression meaning to place an order.

You should learn it as a chunk:

• 下单 = place an order
• 下订单 = place an order

The 下 here is not translated literally as down. In many Chinese expressions, a verb like 下 becomes part of a set phrase. So it is better to remember 下单 as one vocabulary item.

Yes. It follows a very common Chinese order:

subject + adverb + location + verb + particle

So here:

• 我 = subject
• 已经 = adverb
• 在网站上 = location
• 下单 = verb
• 了 = particle

A more literal breakdown is:

I already on the website placed an order.

That kind of order is very normal in Mandarin.

快递 can refer to a few related things depending on context:

• express delivery service
• a courier delivery
• a package sent by courier

In this sentence, it most naturally means something like the delivery/package. So:

快递明天会送到我家 = The package will be delivered to my home tomorrow
or
The delivery will arrive at my home tomorrow

If you want to be more specific:

• 快递员 = the courier/delivery person
• 包裹 = package/parcel

会 often expresses a future event, expectation, or prediction. Here it is similar to will in English.

So:

• 明天会送到我家 = will be delivered to my home tomorrow

Chinese does not have a required future tense ending like English. Instead, it often uses time words such as 明天 and sometimes modal verbs such as 会.

In this sentence, 会 makes the future meaning especially clear and natural.

送 means to send or to deliver.
到 is a result complement showing that the action reaches its destination.

So:

• 送 = deliver
• 送到 = deliver to / deliver so that it arrives

That means:

• 送到我家 = deliver to my home

Using 到 emphasizes the endpoint of the action.

In Chinese, 我家 is the normal everyday way to say my home or my place.

• 我家 = my home / my place
• 我的家 = my home, but more explicit, sometimes more emotional or formal

For close personal relationships and familiar places, Chinese often leaves out 的:

• 我妈 = my mom
• 我爸 = my dad
• 我家 = my home

So 送到我家 sounds very natural.

Because the second clause talks about the future, not a completed action.

• First clause: 已经……了 → something has already happened
• Second clause: 明天会…… → something will happen tomorrow

So 会 is enough to show the future meaning. Adding 了 at the end would change the tone or nuance and is not needed in this basic sentence.

Time words in Chinese usually come before the main verb phrase.

So this order is very common:

subject + time + modal/verb

Here:

• 快递 = subject
• 明天 = time
• 会送到我家 = will be delivered to my home

That is why 快递明天会送到我家 sounds natural.

Yes. Chinese often leaves out information that is already understood from context.

For example, if everyone already knows it was ordered online, you could simply say:

我已经下单了。
= I’ve already placed the order.

Or if the package is understood:

明天会送到我家。
= It will be delivered to my home tomorrow.

Chinese often sounds more natural than English when it omits repeated or obvious information.