Saya tidak hanya membawa amplop dan dokumen, tetapi juga obat flu untuk teman perempuan saya yang sedang bersin.

This is a very common Indonesian pattern meaning not only ..., but also ...

In your sentence:

Saya tidak hanya membawa amplop dan dokumen, tetapi juga obat flu ...

it means:

I brought not only envelopes and documents, but also flu medicine ...

A few useful notes:

• tidak hanya = not only
• tetapi juga = but also
• The two parts usually connect parallel ideas.

So the structure is:

Saya membawa X, dan bukan cuma itu, tetapi juga Y.

In natural English:

• not only X, but also Y

In Indonesian, this pattern is very common in both speech and writing.

Because tidak is used to negate verbs, adjectives, and some other predicates, while bukan is mainly used to negate nouns or noun phrases.

Here, the key word after it is hanya, and the whole phrase tidak hanya is a fixed expression meaning not only.

Also, the sentence centers around the verb membawa (to bring/carry), so tidak is the correct negator.

Compare:

• Saya tidak membawa obat. = I am not bringing medicine.
• Itu bukan obat. = That is not medicine.

So in this sentence, tidak hanya is the natural and correct choice.

Membawa usually means to bring, to carry, or to take along, depending on context.

In this sentence, membawa is best understood as bring / carry:

• Saya membawa amplop = I brought/carried an envelope
• Saya membawa obat flu = I brought flu medicine

It does not by itself mean give.
So the sentence says the speaker has the items with them / took them along, not necessarily that they already handed them over.

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

So:

• amplop can mean an envelope, the envelope, or just envelopes, depending on context.
• dokumen can mean a document, the document, or documents.
• obat flu can mean flu medicine, some flu medicine, or the flu medicine.

Context tells you which meaning is intended.

That is why Indonesian learners of English often have to learn articles, while English speakers learning Indonesian have to get used to not seeing them.

In Indonesian, nouns are often left unmarked for number unless the speaker needs to be specific.

So:

• amplop could be an envelope or envelopes
• dokumen could be a document or documents
• obat flu could be flu medicine in a general or uncountable sense

If Indonesian wants to be very explicit about plurality, it can use reduplication or other clues:

• amplop-amplop = envelopes
• dokumen-dokumen = documents
• numbers, classifiers, or context can also show plurality

In your sentence, English translation may choose singular or plural based on context, but Indonesian itself does not force that choice.

Literally, obat means medicine/remedy and flu means flu.

So obat flu means:

• flu medicine
• medicine for the flu
• sometimes in everyday usage, something closer to cold medicine, depending on context

Indonesian often forms noun combinations like this very simply:

• obat sakit kepala = headache medicine
• obat batuk = cough medicine
• obat flu = flu medicine

So it is a straightforward noun phrase: medicine + illness/problem.

Here, untuk means for.

So:

obat flu untuk teman perempuan saya
= flu medicine for my female friend

It shows the intended recipient or purpose.

A few other common uses of untuk:

• untuk saya = for me
• untuk belajar = for studying / to study
• untuk anak-anak = for children

In your sentence, it connects obat flu to the person who is meant to receive it.

Usually, teman perempuan saya means my female friend, not necessarily my girlfriend.

This is an important point because English speakers often wonder about it.

• teman = friend
• perempuan = female / woman
• teman perempuan = female friend

If someone wants to say girlfriend in the romantic sense, they more commonly say:

• pacar saya = my girlfriend/boyfriend
• sometimes context may clarify romance, but teman perempuan by itself usually sounds like female friend

So in this sentence, the safest reading is my female friend who is sneezing.

Yang introduces a relative clause. In English, this often corresponds to who, that, or which.

So:

teman perempuan saya yang sedang bersin

means:

my female friend who is sneezing

The clause yang sedang bersin describes teman perempuan saya.

A useful way to see it:

• teman perempuan saya = my female friend
• yang sedang bersin = who is currently sneezing

So yang links the noun to the description that follows it.

Sedang shows that an action is in progress, similar to English is/are ...-ing.

So:

• bersin = sneeze / to sneeze
• sedang bersin = is sneezing / currently sneezing

Therefore:

teman perempuan saya yang sedang bersin
= my female friend who is sneezing

Without sedang, you could still say:

teman perempuan saya yang bersin

That can also mean my female friend who sneezes / who sneezed / who is sneezing, depending on context.
Adding sedang makes the ongoing action clearer.

Bersin means to sneeze.

It looks like it has the prefix ber-, and historically that is true, but for learners it is best to treat bersin as a whole vocabulary item.

The prefix ber- often forms intransitive verbs, especially actions or states connected with the subject.

Some examples:

• berjalan = to walk
• berbicara = to speak
• berenang = to swim
• bersin = to sneeze

So in this sentence:

yang sedang bersin = who is sneezing

It describes teman perempuan saya, not obat flu and not the whole sentence.

So the structure is:

• obat flu
• untuk teman perempuan saya
• yang sedang bersin

This means:

flu medicine for my female friend, who is sneezing

The sneezing person is the friend.

A learner-friendly way to group it is:

[Saya] [tidak hanya membawa amplop dan dokumen] [tetapi juga obat flu] [untuk teman perempuan saya yang sedang bersin].

The first saya is the subject:

• Saya ... membawa ... = I ... brought ...

The second saya shows possession:

• teman perempuan saya = my female friend

So they have different roles:

• first saya = I
• second saya = my

This is completely normal in Indonesian.

Yes, it is grammatical and understandable. It sounds fairly natural.

A native speaker might also say slightly different versions depending on style:

• Saya tidak hanya membawa amplop dan dokumen, tetapi juga membawa obat flu untuk teman perempuan saya yang sedang bersin.
• Saya bukan hanya membawa amplop dan dokumen, tetapi juga obat flu untuk teman perempuan saya yang sedang bersin.

The original sentence is already good.
One small stylistic point: some speakers may repeat membawa after tetapi juga for extra balance, but it is not required.

Yes.

• tetapi is the more formal/full form
• tapi is the common spoken and informal form

So in casual speech, many people would say:

Saya tidak hanya membawa amplop dan dokumen, tapi juga obat flu untuk teman perempuan saya yang sedang bersin.

Both are correct. The difference is mainly register:

• tetapi = more formal/written
• tapi = more conversational

Yes, a little.

The biggest possible ambiguity is teman perempuan saya:

• usually my female friend
• but an English reader might wonder whether it means girlfriend

Another small issue is number:

• amplop could be an envelope or envelopes
• dokumen could be a document or documents

Indonesian often leaves these things to context, so translators have to choose the most natural English wording based on the situation.