Learn Hardcore Indonesian: Saya simpan nomor kontak dokter di telepon. - I keep the doctor's contact number in the phone.

menyimpan = the standard, fully inflected verb, often more neutral/formal
- Saya menyimpan nomor kontak dokter di telepon.
simpan = the bare root verb, very common in spoken / informal Indonesian
- Saya simpan nomor kontak dokter di telepon.

In everyday conversation and informal writing (texts, chat), you’ll often hear/see the root form: saya simpan, saya ambil, saya taruh, etc.
In formal writing or exams, Saya menyimpan… is safer and more “correct” stylistically.

Should it be di telepon or di telepon saya? How do Indonesians usually say “in my phone”?

di telepon literally means “in/on the telephone”. Context usually makes it clear that you mean your own phone, so people often omit saya.

All of these are possible:

Saya simpan nomor kontak dokter di telepon.
= I saved the doctor’s contact number in my (the) phone. (Context-dependent)
Saya simpan nomor kontak dokter di telepon saya.
= I saved the doctor’s contact number in my phone. (Explicit)
Very common in speech:
- di HP saya (HP = handphone, very common)
- di ponsel saya

If you want to be very clear and natural in everyday speech, di HP saya or di ponsel saya is often more idiomatic than di telepon saya.

What exactly does di telepon mean – “in the phone” or “on the phone”?

Indonesian di covers several English prepositions:

di = at / in / on (location)

So di telepon can be translated as:

“in the phone” (stored inside the device)
“on the phone” (also acceptable in English for digital storage)

Indonesian doesn’t distinguish with different prepositions the way English does; di is the default location preposition. The exact English translation depends on what sounds natural in English: here, “in my phone” or “in my contacts” is usually best.

Why is it nomor kontak dokter and not something like nomor dokter kontak? What is the word order rule?

Indonesian noun phrases generally go:

Main noun + describing words (other nouns / adjectives / possessors) after it.

In nomor kontak dokter:

nomor = main noun (“number”)
kontak dokter = describes what kind of number (“the doctor’s contact”)

You can think of it like layered descriptions:

nomor (number)
nomor kontak (contact number)
nomor kontak dokter (the doctor’s contact number)

Reordering them (e.g. nomor dokter kontak) would sound wrong or very confusing to Indonesians.

Is there any difference between nomor kontak dokter and nomor dokter?

Yes, there’s a nuance:

nomor dokter
= the doctor’s number
(by default, people assume phone number)
kontak dokter
= the doctor’s contact (could include phone, email, address, etc.)
nomor kontak dokter
= the number of the doctor’s contact
→ basically “the doctor’s contact number”

In everyday conversation, people very often just say:

Saya simpan nomor dokter di telepon.
(totally natural and shorter)

nomor kontak dokter is still correct; it just sounds a bit more explicit or bookish.

If I want to say “my doctor’s contact number”, should it be nomor kontak dokter saya?

Yes, that’s the normal way:

nomor kontak dokter saya = my doctor’s contact number

Structure:

nomor (number)
kontak (contact)
dokter saya (my doctor)

You can also say:

nomor dokter saya = my doctor’s number
kontak dokter saya = my doctor’s contact (in general)

The possessor (saya, dia, etc.) usually comes last in the noun phrase:

rumah saya (my house)
nomor telepon dia (his/her phone number)
kontak dokter saya (my doctor’s contact)

There is no word for “the” in this sentence. How do we know it’s “the doctor’s number” and not “a doctor’s number”?

Indonesian has no articles like “a/an/the”. The sentence:

Saya simpan nomor kontak dokter di telepon.

could be:

I saved the doctor’s contact number in my phone.
I saved a doctor’s contact number in my phone.

Context tells you which is meant. If you want to make it clearly “that specific doctor”, you can add:

dokter itu = that doctor
- Saya simpan nomor kontak dokter itu di telepon.

Or if it’s your regular doctor:

dokter saya = my doctor
- Saya simpan nomor kontak dokter saya di telepon.

How do we know the tense? Does saya simpan mean “I saved” or “I am saving”?

Indonesian verbs do not change form for tense. So:

Saya simpan nomor kontak dokter di telepon.

can mean:

I save the doctor’s contact number in my phone. (habit)
I am saving the doctor’s contact number in my phone. (right now)
I saved the doctor’s contact number in my phone. (past)

Context decides.
If you want to be explicit:

Saya sudah simpan… = I already saved… (past / completed)
Saya sedang menyimpan… = I am saving… (right now)
Saya akan simpan… = I will save… (future)

Can I drop Saya and just say Simpan nomor kontak dokter di telepon?

Yes, but the meaning changes:

Saya simpan nomor kontak dokter di telepon.
= I (statement about what I did/do)
Simpan nomor kontak dokter di telepon.
= (You) save the doctor’s contact number in the phone. → sounds like a command / instruction.

In Indonesian, dropping the subject often turns the sentence into an imperative (a command), especially when using the root verb form:

Buka pintunya. = Open the door.
Ambil buku itu. = Take that book.

So keep Saya if you want it clearly as a statement about yourself.

Is this sentence formal, informal, or neutral? Would it be okay in polite conversation?

Using the root verb simpan makes it sound informal / conversational, but still polite.
With menyimpan, it becomes more neutral/standard:
- Saya menyimpan nomor kontak dokter di telepon.
  → suitable for writing, formal speech, or talking to strangers politely.

In ordinary spoken Indonesian with friends, family, or colleagues, the original:

Saya simpan nomor kontak dokter di telepon.

is perfectly natural and acceptable.