Telefon baharu ini masih ada jaminan selama setahun.

In Malay, adjectives usually come after the noun they describe.

• telefon baharu = new phone
• kereta merah = red car
• rumah besar = big house

So telefon baharu is the normal Malay word order: noun + adjective.

In Malay, demonstratives like ini (this) and itu (that) normally come after the whole noun phrase.

So:

• telefon baharu ini = this new phone
• rumah besar itu = that big house

The pattern is often:

noun + adjective + ini/itu

So even though English says this new phone, Malay says something closer to phone new this.

Both can mean new.

However:

• baru is much more common in everyday speech
• baharu is more formal and often appears in careful writing, news, advertisements, or official language

One reason baharu is useful is that baru can also mean just / only recently, so baharu can sound clearer in formal contexts.

For example:

• telefon baru = new phone
• baru sampai = just arrived

In this sentence, baharu simply means new.

Masih means still.

In this sentence, it shows that the warranty is still valid now. The phone continues to have warranty coverage.

So:

• masih ada jaminan = still has a warranty / is still under warranty

Common related words:

• masih = still
• sudah = already
• tidak lagi = no longer

Malay often uses ada to express existence or possession.

• ada can mean there is/are
• in context, it can also mean have/has

So:

• Telefon ini ada jaminan = This phone has a warranty
• literally, it is something like There is warranty for this phone

This is very natural Malay. You could also say:

• Telefon ini mempunyai jaminan

But mempunyai sounds more formal. Ada jaminan is simple and common.

It can mean either, depending on context.

• In everyday consumer/product contexts, jaminan often means warranty
• In more general contexts, it can also mean guarantee or assurance

Here, because the sentence is about a phone and a period of one year, warranty is the most natural translation.

Malay does not normally use articles like a, an, or the the way English does.

So:

• jaminan can mean a warranty or just warranty, depending on context

Malay often leaves this unstated unless it really needs to be specific.

That is why ada jaminan naturally translates as has a warranty, even though there is no separate word for a.

Selama means for or for a period of when talking about duration.

So:

• selama setahun = for one year

It tells you the length of time the warranty lasts.

Compare:

• selama dua hari = for two days
• selama sebulan = for one month

In this sentence, selama setahun describes the duration of the warranty.

Setahun is a very common way to say one year.

The prefix se- can mean one:

• setahun = one year
• sebulan = one month
• seminggu = one week
• sehari = one day

You can also say satu tahun, and it is understandable, but setahun sounds more natural in many cases, especially after words like selama.

So:

• selama setahun = very natural
• selama satu tahun = also possible, but often less smooth

Yes, that is grammatical.

However, there is a style difference:

• masih ada jaminan = more natural, simple, everyday
• masih mempunyai jaminan = more formal or more written

Both mean basically the same thing here. If you are speaking casually, ada jaminan is usually the better choice.

A natural way is:

Telefon baharu ini tidak lagi ada jaminan selama setahun.

But depending on the exact meaning, Malay speakers might phrase it more naturally as:

• Telefon baharu ini sudah tidak ada jaminan lagi. = This new phone no longer has a warranty.
• Jaminan telefon baharu ini sudah tamat. = The warranty for this new phone has already expired.

That last version is especially natural if you mean the warranty period has ended.