Tôi đã hẹn thời gian sửa chữa.

đã marks that the action of hẹn has already happened.

So in Tôi đã hẹn thời gian sửa chữa, the repair itself may still be in the future, but the scheduling/arranging has already been done.

A good way to think about it is:

• đã hẹn = already arranged / scheduled
• not necessarily already repaired

Vietnamese does not mark tense the same way English does. Words like đã, đang, and sẽ often help show time, but they are not used exactly like English past/present/future verb forms.

No. It usually means only that the appointment or time has been arranged.

That is an important distinction:

• Tôi đã hẹn thời gian sửa chữa. = I have already set up the repair time.
• It does not mean: I repaired it already.

If you wanted to say the repair itself was completed, Vietnamese would need a different verb structure, for example something based on sửa xong or đã sửa xong.

In this sentence, hẹn means something like to arrange, to make an appointment, or to agree on a time.

Common uses of hẹn include:

• hẹn gặp = arrange to meet
• hẹn giờ = set a time
• hẹn lịch = schedule an appointment
• hẹn ngày = set a day

So here, hẹn is about fixing a time for the repair.

Depending on context, English translations could be:

• I scheduled the repair time.
• I arranged a time for the repair.
• I made a repair appointment.

Because Vietnamese word order is usually:

• subject + time marker + verb + object/complement

So here:

• Tôi = I
• đã = already
• hẹn = arranged / scheduled
• thời gian sửa chữa = the repair time / time for repair

That makes the structure:

Tôi + đã + hẹn + thời gian sửa chữa.

This is very normal Vietnamese word order.

thời gian sửa chữa literally means repair time or time for repair.

Breaking it down:

• thời gian = time
• sửa chữa = repair / repairing

Together, it refers to the time slot, period, or appointment related to the repair.

In English, we often make this sound more natural by saying:

• a time for the repair
• the repair appointment
• the repair time

It is originally a verb meaning to repair, but in this sentence it works more like a modifier describing what kind of thời gian it is.

So:

• thời gian sửa chữa = time for repairing / repair time

This is very common in Vietnamese. A verb can follow a noun and describe its purpose or function.

Similar patterns:

• kế hoạch học tập = study plan
• phòng họp = meeting room
• thời gian làm việc = working hours

So even though sửa chữa is verbal in origin, here it helps form a noun phrase.

It is understandable, but many native speakers might say it a little differently depending on context.

More natural alternatives often include:

• Tôi đã hẹn lịch sửa chữa.
• Tôi đã đặt lịch sửa chữa.
• Tôi đã hẹn giờ sửa chữa.
• Tôi đã sắp xếp thời gian sửa chữa.

The difference is subtle:

• hẹn lịch / đặt lịch sounds very natural for appointments
• hẹn giờ emphasizes the specific time
• sắp xếp thời gian emphasizes arranging the timing

So your sentence is grammatically understandable, but in everyday speech, đặt lịch sửa chữa or hẹn lịch sửa chữa may sound smoother.

Vietnamese does not use articles like English a/an/the.

So thời gian sửa chữa could mean:

• a repair time
• the repair time
• repair time

The exact meaning depends on context.

For example:

• If both speakers already know which repair is being discussed, it may feel like the repair time.
• If it is being mentioned more generally, it may feel like a time for repair.

This is very normal in Vietnamese, and learners usually need to rely on context more than in English.

Yes, very often.

If the subject is clear from context, Vietnamese can drop pronouns. For example:

• Đã hẹn thời gian sửa chữa rồi.

This could still mean I’ve already scheduled the repair time, if the context makes that obvious.

Native speakers omit tôi quite often in conversation when there is no risk of confusion.

Both can be used for scheduling, but they are not exactly the same in tone.

• hẹn = arrange/agree on a time, often with another person
• đặt lịch = book/schedule an appointment, often a bit more practical or service-related

For repairs, especially with a service center or technician, đặt lịch sửa chữa is extremely natural.

Examples:

• Tôi đã hẹn với thợ sửa xe.
  = I arranged with the mechanic.

• Tôi đã đặt lịch sửa chữa.
  = I booked a repair appointment.

So in your sentence, hẹn is fine, but đặt lịch may sound more idiomatic in many real-life situations.

Yes, that is a very good natural English translation.

Even if the Vietnamese sentence literally mentions time, English often prefers a more natural phrase like:

• I made a repair appointment.
• I scheduled the repair.
• I arranged a time for the repair.

That is a good example of how a natural translation does not always need to match each word one-for-one.