Kayaknya aku mau jajan sesuatu yang manis di toko roti dekat sini.

It seems like I want to buy a snack—something sweet—at the bakery near here.

Breakdown of Kayaknya aku mau jajan sesuatu yang manis di toko roti dekat sini.

• di: at
• dekat: near
• manis: sweet
• yang: that
• mau: want
• sini: here
• aku: I
• toko roti: the bakery
• kayaknya: it seems like
• jajan: to buy a snack
• sesuatu: something

Questions & Answers about Kayaknya aku mau jajan sesuatu yang manis di toko roti dekat sini.

What does kayaknya mean here, and how strong is it?

Kayaknya is a colloquial form of kayaknya/kayak-nya meaning it seems / I think / looks like. It softens what you’re saying: you’re not stating a firm plan, more like a likely intention or impression.
More neutral/formal alternatives: sepertinya, kelihatannya.

Is aku informal? When would I use saya instead?

Yes. Aku is common in casual speech with friends, family, peers, and in many informal contexts. Saya is more neutral/polite and common in formal situations, with strangers, at work (depending on culture), customer service, etc.
The rest of the sentence (especially kayaknya, jajan) also feels casual, so aku matches the register.

Does mau mean want to or going to?

It can express both, depending on context. In this sentence it naturally means I feel like / I’m going to (intend to) buy a snack.

• Desire focus: Aku mau jajan = I want to snack/buy snacks.
• Intention/near-future: Aku mau ke toko roti = I’m going to the bakery.

What exactly does jajan mean? Is it just buy?

Jajan means to buy snacks / to snack (by buying food), often small treats like pastries, street food, sweets. It’s more specific and more cultural than beli (buy).

• beli = general purchase
• jajan = snack/treat purchase (often impulsive, casual)

Can jajan be used without an object, and is this sentence missing anything after jajan?

Yes, jajan can stand alone: Aku mau jajan = I want to buy some snacks / I want to get a treat.
Here it does have an object: sesuatu yang manis (something sweet).

How does sesuatu yang manis work grammatically?

sesuatu = something
yang links a noun to a describing phrase (like a relative clause/adjective marker).
manis = sweet
So sesuatu yang manis literally = something that is sweet.

When do I use yang like this, and can I omit it?

Use yang when a description follows the noun as a clause/phrase:

• orang yang baik = a person who is kind
• kue yang enak = a cake that’s tasty
  You usually don’t omit yang in this pattern. Without it, it can sound unnatural or change the feel. sesuatu manis might be understood, but sesuatu yang manis is the standard phrasing.

Why is it di toko roti and not ke toko roti?

di marks location: at/in the bakery. It focuses on where the buying happens.
ke marks direction: to the bakery (movement).

• …jajan … di toko roti = snack-buying at the bakery
• …mau ke toko roti = intend to go to the bakery
  You can combine both ideas: Kayaknya aku mau ke toko roti dekat sini buat jajan sesuatu yang manis.

What does toko roti literally mean, and is it the same as a bakery?

Literally toko = shop, roti = bread, so bread shop. In Indonesian usage, toko roti commonly means bakery (a shop selling bread/pastries).

How does dekat sini work, and where does it go in the sentence?

dekat sini = near here / nearby. It can modify the place phrase:

• di toko roti dekat sini = at the bakery near here
  It can also be moved for emphasis, but the given placement is very natural.

Is the word order fixed? Could I say it differently and still sound natural?

Indonesian is fairly flexible. Some natural alternatives:

• Kayaknya aku mau jajan yang manis-manis di toko roti dekat sini. (more casual, sweet things)
• Sepertinya aku mau beli sesuatu yang manis di toko roti dekat sini. (more neutral, uses beli)
• Aku kayaknya mau jajan sesuatu yang manis di toko roti dekat sini. (same meaning, different placement)

What register does this whole sentence have? Would it sound okay in formal writing?

It’s casual/conversational because of kayaknya, aku, and jajan. In formal writing you’d likely use something like:
Sepertinya saya ingin membeli sesuatu yang manis di toko roti dekat sini.