wǒ yùdìng le zhè jiā jiǔdiàn.

Here, 了 marks a completed action: the booking has been made.

So 我预订了这家酒店 means that the speaker has already finished the act of reserving the hotel.

A key point: 了 is not exactly the same as an English past tense marker. It shows aspect (completion), not simply “past time.” In many everyday situations, though, it often ends up being translated as past tense in English.

家 is a measure word / classifier.

In Chinese, when a noun is preceded by a demonstrative like 这 (this) or a number like 一 (one), you usually need a classifier:

• 这家酒店 = this hotel
• literally: this + classifier + hotel

家 is commonly used for businesses and establishments, such as:

• 酒店 hotel
• 餐厅 restaurant
• 公司 company
• 商店 shop

So 这家酒店 sounds natural and correct.

Yes, 这个酒店 is understandable and grammatical, because 个 is a very common general classifier.

However, 这家酒店 is usually more natural and more precise, because 家 is the classifier that specifically fits places like hotels, stores, and companies.

So:

• 这家酒店 = more natural
• 这个酒店 = acceptable, but less specific

Both can mean to book / reserve.

• 预订 is a bit more formal and emphasizes reserving in advance
• 订 is shorter and very common in everyday speech

So these are both natural:

• 我预订了这家酒店。
• 我订了这家酒店。

The first sounds slightly more formal or written.

No. In normal usage, it usually means I booked a stay at this hotel, not that you reserved the entire building.

Chinese often allows the place itself to be the object of 预订 / 订. In context, people understand that you mean a room or accommodation there.

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

• 我在这家酒店订了房间。 = I booked a room at this hotel.
• 我预订了这家酒店的房间。 = I reserved a room in this hotel.

The normal order in Chinese is:

demonstrative + classifier + noun

So:

• 这 = this
• 家 = classifier
• 酒店 = hotel

Together: 这家酒店

This pattern is extremely common in Mandarin:

• 这本书 = this book
• 那个人 = that person
• 这家公司 = this company

So 这家酒店 follows a standard Chinese noun pattern.

This is because the 了 here is the verb-related 了, which marks that the action is completed.

Structure:

• 我 预订了 这家酒店
• subject + verb + 了
  • object

Chinese actually has more than one use of 了:

1. verb 了: marks completion
   
   • 我预订了这家酒店。
2. sentence-final 了: often marks a new situation or change
   
   • 我预订这家酒店了。

The first one is the most straightforward form for saying the booking was completed.

This is a great example of why Chinese words should not always be translated character by character.

Although:

• 酒 = alcohol / wine
• 店 = shop / store

the compound 酒店 is a fixed modern word meaning hotel.

Historically, words like this developed from older meanings connected with inns and places serving food or drink. In modern Mandarin, though, 酒店 simply means hotel.

So it is best to learn 酒店 as one vocabulary word.

Sometimes, yes.

Chinese often drops the subject when it is already clear from context. So in conversation, if everyone knows you are talking about yourself, you might just say:

• 预订了这家酒店。

But as a standalone sentence for learners, 我预订了这家酒店。 is clearer and more complete.

Not exactly. It is better to say it describes a completed action, not a tense in the same way English does.

Because of 了, the sentence usually refers to something that has already been done, so English often translates it as past:

• I booked this hotel.

But the grammar is really about completion, not a dedicated past-tense ending. That is an important difference between Chinese and English.