Learn Hardcore Indonesian: Kacamata itu cocok dengan topi biru kamu.

It marks the noun as specific/definite, roughly that/those or the. So kacamata itu means those glasses / that pair of glasses (the ones we both know or can see). Without itu, it sounds more general.

Is kacamata singular or plural?

Indonesian doesn’t mark number by default. Kacamata is a fixed noun meaning eyeglasses and usually refers to one pair. Context decides singular/plural. To be explicit:

one pair: sebuah kacamata or satu kacamata
several pairs: beberapa kacamata, dua (buah) kacamata

Why is biru after topi?

Adjectives normally follow the noun in Indonesian. So topi biru (hat blue) = blue hat. You can also say topi yang biru to single out the blue one among several hats.

Why is kamu at the end of topi biru kamu? Can I use -mu?

Possessors come after the noun phrase. All of these are correct:

topi biru kamu (your blue hat; everyday neutral)
topi birumu (your blue hat; uses the clitic -mu, a bit more compact/neutral)
topi kamu yang biru (the blue one among your hats; adds contrast)

How formal is kamu? What are formal options?

kamu is informal. For formal or polite speech:

Use Anda: topi biru Anda
Or use titles/names: topi biru Bapak/Ibu/Suster/Dokter (very common and polite)

Where is the verb “to be” (are/is) in this sentence?

Indonesian doesn’t use a separate “to be” before adjectives/stative verbs. cocok itself functions as the predicate (matches/is suitable). You do not add adalah here.

Why is it cocok dengan and not just cocok?

When you mention what something matches, cocok typically takes dengan (with). So: cocok dengan topi biru kamu. Colloquially you’ll also hear cocok sama.

What’s the difference between cocok dengan and cocok untuk?

cocok dengan X = matches/goes well with X (two items that coordinate)
cocok untuk X = suitable/appropriate for X (a purpose, person, or situation) Example: Kacamata itu cocok untuk wajah bulat (those glasses are suitable for a round face).

Are there synonyms for cocok here?

Yes:

serasi (dengan): more elegant/poetic (harmonious with)
pas (dengan): informal (fits/goes well with)
klop (dengan): very informal/slangy (in sync with)

How do I negate the sentence?

Use tidak before the predicate: Kacamata itu tidak cocok dengan topi biru kamu (Those glasses don’t match your blue hat).

How can I add emphasis like really?

Common intensifiers:

Formal/neutral: sangat cocok (very), cukup cocok (quite)
After the predicate: cocok sekali (very)
Informal: cocok banget (really) Example: Kacamata itu cocok banget dengan topi biru kamu.

What’s the difference between kacamata itu and itu kacamata?

kacamata itu = that/those glasses (a noun phrase; subject of the sentence)
itu kacamata = that is/those are glasses (an identification; This/That = glasses) Your sentence needs kacamata itu.

Can I use ini instead of itu?

Yes. kacamata ini means this/these glasses (near the speaker or just introduced). So: Kacamata ini cocok dengan topi biru kamu.

Can I also mark the hat as specific, like topi biru kamu itu?

Yes. topi biru kamu itu = that blue hat of yours (a particular one). Full sentence: Kacamata itu cocok dengan topi biru kamu itu. It sounds heavier but is fine when both items are known/specific.

How do I talk about multiple hats?

Options:

Keep it unmarked and let context imply plural: topi biru kamu
Explicit plural (more written/formal): topi-topi biru kamu
With quantity words: beberapa topi biru kamu (several of your blue hats)

Does kacamata mean sunglasses too?

By default kacamata = eyeglasses. Specify type with another word:

kacamata hitam = sunglasses
kacamata renang = swimming goggles
kacamata baca = reading glasses

Is kacamata written as one word? What about pronunciation?

Spelling: standard is one word kacamata (not kaca mata). Note mata kaca would mean a glass eye (different meaning).
Quick pronunciation tips:
- c = ch (like church): cocok ≈ cho-chok, kacamata ≈ ka-cha-ma-ta
- u sounds like oo (food): kamu, biru
- ng in dengan is like sing; the first e is a schwa (uh)