Jahitan itu rosak sejak saya membeli pakaian ini.

Jahitan means stitching, seam, or the sewn part of a garment.

It comes from the root jahit, which means to sew.

So:

• jahit = to sew
• jahitan = stitching / seam / sewn work

In this sentence, jahitan itu most naturally means the stitching or that seam.

In Malay, demonstratives such as ini (this) and itu (that/the) usually come after the noun, not before it.

So:

• jahitan itu = that stitching / the stitching
• pakaian ini = this clothing / this garment

This is one of the first word-order differences English speakers notice:

• English: this garment
• Malay: pakaian ini

They are pointing to different things:

• jahitan itu = that/the stitching
• pakaian ini = this clothing / this garment

Malay allows ini and itu in the same sentence as long as they refer to different nouns or help show contrast.

Here, the speaker is talking about:

1. a particular seam/stitching, and
2. this item of clothing

So the sentence is not contradictory.

Rosak is often translated as damaged, broken, or spoiled. In this sentence, it functions like a predicate adjective or stative verb.

Malay often does not need a separate word for is.

So:

• Jahitan itu rosak literally looks like the stitching damaged
• but naturally it means The stitching is damaged

This is normal Malay sentence structure.

Malay usually does not use a copula like English is/am/are in simple statements of description.

So:

• Dia cantik = She is beautiful
• Rumah itu besar = That house is big
• Jahitan itu rosak = The stitching is damaged

English requires is, but Malay usually does not.

Sejak means since or ever since.

It introduces the starting point of a situation that continues afterward.

In this sentence:

• sejak saya membeli pakaian ini = since I bought this garment

So the idea is that the stitching has been in a damaged state from the time of purchase onward.

Membeli is the meN- form of beli (to buy). It is the more standard/formal active verb form.

So:

• saya membeli pakaian ini = I bought this garment
• saya beli pakaian ini = I bought this garment

Both are used, but they feel slightly different:

• membeli = more formal, careful, written, standard
• beli = more conversational, everyday speech

A native speaker might very naturally say:

• Jahitan itu rosak sejak saya beli pakaian ini.

Malay does not change the verb for tense the way English does.

Instead, Malay often relies on:

• time words
• context
• aspect markers such as sudah
• words like sejak

Here, sejak already tells you that the state started in the past and continues from that point.

So Jahitan itu rosak sejak saya membeli pakaian ini can naturally correspond to English:

• The stitching has been damaged since I bought this garment
• The stitching has been defective ever since I bought this garment

If you want to make the ongoing/resulting state even clearer, you could add sudah:

• Jahitan itu sudah rosak sejak saya membeli pakaian ini.

Malay nouns usually do not mark singular/plural the way English does.

So pakaian can mean:

• clothing
• clothes
• a garment
• an item of clothing

The exact meaning depends on context.

In this sentence, because the speaker mentions a specific stitching problem, pakaian ini is most likely understood as:

• this garment
• this item of clothing

That is often more natural in English than these clothes here.

Yes, it is understandable and grammatically acceptable, but a native speaker might choose a slightly more natural version depending on the situation.

Possible alternatives include:

• Jahitan pakaian ini rosak sejak saya membelinya.
• Jahitan pada pakaian ini rosak sejak saya membelinya.
• Jahitan pakaian ini sudah rosak sejak saya beli lagi.
  (more colloquial, depending on region and context)

Why might someone rephrase it? Because jahitan itu sounds like the listener already knows which seam is being referred to, while pakaian ini introduces the garment itself. A speaker might prefer to connect them more directly.

Still, the original sentence is perfectly understandable.

Yes. In many contexts, itu can function a bit like that, but in natural translation it is often better rendered as the when the noun is already identifiable.

So jahitan itu could be:

• that stitching
• the stitching

Which translation fits best depends on context.

English speakers often over-translate itu as that, but sometimes the sounds more natural.

A more casual spoken version could be:

Jahitan tu rosak sejak saya beli pakaian ni.

Changes:

• itu → tu
• ini → ni
• membeli → beli

This is very common in conversation, while the original version sounds more standard or written.