Thợ máy sửa đèn xi-nhan.

It follows the very common Vietnamese pattern:

• Subject: thợ máy = mechanic
• Verb: sửa = repair, fix
• Object: đèn xi-nhan = turn signal light

So the structure is Subject + Verb + Object, just like English in a simple sentence.

Thợ máy is a fixed expression meaning mechanic.

• thợ = worker, craftsman, skilled repair person
• máy = machine

Together, they describe someone who works on machines, so thợ máy means mechanic.

In natural Vietnamese, this is a normal way to build nouns: one word gives the general role, and another word narrows it down.

Vietnamese usually does not use articles the way English does.

So thợ máy can mean:

• a mechanic
• the mechanic
• sometimes even mechanics in the right context

And đèn xi-nhan can mean:

• a turn signal light
• the turn signal light
• turn signal lights

Context tells you which one is meant. If Vietnamese needs to be more specific, it can add words such as:

• một for a/one
• này for this
• đó/kia for that

Example:

• Người thợ máy sửa cái đèn xi-nhan này. = The mechanic fixes this turn signal light.

No. Vietnamese verbs do not change form for tense.

The verb sửa stays the same. Time is usually shown by context or by extra words such as:

• đã = past
• đang = currently, in progress
• sẽ = future

Examples:

• Thợ máy đã sửa đèn xi-nhan. = The mechanic fixed the turn signal light.
• Thợ máy đang sửa đèn xi-nhan. = The mechanic is fixing the turn signal light.
• Thợ máy sẽ sửa đèn xi-nhan. = The mechanic will fix the turn signal light.

Here sửa means to repair or to fix.

It is a very common verb and can be used for many kinds of things:

• sửa xe = repair a vehicle
• sửa máy = repair a machine
• sửa điện thoại = repair a phone

Depending on context, sửa can also mean to correct or to edit, not just physically repair something.

For example:

• sửa bài = correct homework
• sửa lỗi = fix an error

But in this sentence, because the object is đèn xi-nhan, the meaning is clearly repair.

• đèn = lamp, light
• xi-nhan = signal, especially a vehicle turn signal / indicator

So đèn xi-nhan is the turn signal light or indicator light on a vehicle.

In everyday speech, people may also say just xi nhan in some contexts, especially when talking about signaling while driving, as in:

• bật xi nhan = turn on the turn signal

Because classifiers are often omitted when a noun is being used in a general way as the object of a verb.

So sửa đèn xi-nhan is perfectly natural.

A classifier becomes more likely when you want to count or point to a specific item:

• sửa một cái đèn xi-nhan = repair one turn signal light
• sửa cái đèn xi-nhan đó = repair that turn signal light

In the original sentence, the object is general enough that no classifier is needed.

By itself, it does not clearly force singular or plural.

Depending on context, it could mean:

• one turn signal light
• the turn signal system
• turn signal lights in general

If you want to be specific, Vietnamese can say:

• một cái đèn xi-nhan = one turn signal light
• hai cái đèn xi-nhan = two turn signal lights

So, as in many Vietnamese sentences, number is often left for context to explain.

Xi-nhan is a loanword, not an old native Vietnamese word. It comes from foreign influence and is commonly used in everyday speech for vehicle signaling.

You may see it written in different ways, such as:

• xi-nhan
• xi nhan

The hyphen is an older or more traditional way of writing some borrowed words. Modern spelling in everyday writing often leaves the hyphen out. Both forms are understandable.

The tone pattern is:

• thợ = nặng tone
• máy = sắc tone
• sửa = hỏi tone
• đèn = huyền tone
• xi = level tone
• nhan = level tone

So the sentence has a mix of tones, which is very normal in Vietnamese.

A rough learner-friendly pronunciation guide would be:

• thợ máy ≈ mechanic, with a heavy clipped tone on thợ and a rising tone on máy
• sửa ≈ a rising-dipping sound
• đèn ≈ a low falling tone
• xi-nhan ≈ two level syllables

The exact pronunciation is best learned by listening, because Vietnamese tones matter a lot.

It is a complete and natural Vietnamese sentence, but it sounds a little plain and context-free, like:

• a simple statement
• a textbook example
• a caption
• a description of what someone does

In real conversation, speakers often add more detail, such as time, aspect, or a specific person:

• Người thợ máy đang sửa đèn xi-nhan. = The mechanic is fixing the turn signal light.
• Anh thợ máy sửa đèn xi-nhan rồi. = The mechanic has already fixed the turn signal light.

So the original sentence is correct and natural, just very basic.

Yes. That is also correct.

• thợ máy = mechanic
• người thợ máy = mechanic, with người making the personhood more explicit

Adding người can sound a bit fuller, but it is not required. In many sentences, thợ máy by itself is perfectly natural.

So both are possible:

• Thợ máy sửa đèn xi-nhan.
• Người thợ máy sửa đèn xi-nhan.

The version without người is shorter and very common.

For a question, one natural way is to add không:

• Thợ máy sửa đèn xi-nhan không? = Is the mechanic fixing the turn signal light?

A more complete conversational version might be:

• Thợ máy có sửa đèn xi-nhan không?

For a negative sentence, use không before the verb:

• Thợ máy không sửa đèn xi-nhan. = The mechanic does not fix the turn signal light.

If you want to say not yet, Vietnamese often uses:

• Thợ máy chưa sửa đèn xi-nhan. = The mechanic has not fixed the turn signal light yet.