Saya membuat sandwich dengan mayones, jagung, dan sedikit selada untuk bekal besok.

Yes. Saya and aku both mean I, but they differ in formality.

• saya = neutral, polite, standard
• aku = more casual, personal, informal

So:

• Saya membuat sandwich... sounds natural in standard speech and writing.
• Aku membuat sandwich... is also correct, but more informal.

If you are learning and want the safest option, saya is a good default.

Yes, there are a few possibilities.

• membuat = to make; standard and common
• buat = can mean make, but is also very often used as for in casual Indonesian
• membikin = also means to make, but is less common in many contexts than membuat

In this sentence, membuat sandwich means make a sandwich.

You could hear:

• Saya membuat sandwich... — standard
• Saya bikin sandwich... — very common and casual
• Saya buat sandwich... — possible in casual speech, but can sometimes sound less clear because buat also has other uses

For learners, membuat is a very good formal/neutral choice, and bikin is a very common everyday alternative.

Indonesian does not usually use articles like a, an, or the the way English does.

So:

• sandwich can mean a sandwich, the sandwich, or just sandwich/sandwiches, depending on context.

In this sentence, the meaning is naturally understood as a sandwich because the context makes it clear.

If you really wanted to emphasize one sandwich, you could say:

• sebuah sandwich = one/a sandwich

But in everyday Indonesian, that would often sound unnecessary here.

In Indonesian, nouns usually do not change form for singular vs. plural.

So sandwich can mean:

• sandwich
• sandwiches

Context tells you which one is meant.

If you want to make the plural explicit, you can use reduplication:

• sandwich-sandwich = sandwiches

Or add a quantity word:

• dua sandwich = two sandwiches
• beberapa sandwich = several sandwiches

In your sentence, it most naturally sounds like one sandwich, but the word itself does not mark singular.

Here, dengan means with.

In this sentence:

• sandwich dengan mayones, jagung, dan sedikit selada
  = a sandwich with mayonnaise, corn, and a little lettuce

Dengan is very common and can be used for several kinds of with, such as:

• accompaniment: Saya pergi dengan teman saya = I went with my friend
• means/method: Saya menulis dengan pensil = I write with a pencil
• ingredients/additions: roti dengan keju = bread with cheese

So here it introduces the fillings or ingredients.

Yes, this is very similar to English listing.

The structure is:

• item 1 + comma
• item 2 + dan
• final item

So:

• mayones, jagung, dan sedikit selada
  = mayonnaise, corn, and a little lettuce

This works much like English. The conjunction dan means and.

In casual writing, some people may omit commas more freely, but this version is clear and natural.

Sedikit means a little, a small amount of, or a few, depending on the noun.

Here:

• sedikit selada = a little lettuce

In Indonesian, quantity words like sedikit usually come before the noun:

• sedikit air = a little water
• sedikit gula = a little sugar
• sedikit selada = a little lettuce

So the word order is different from English only in the sense that there is no extra article like a.

Usually, no, not in this meaning.

If you want to say a little lettuce, the natural order is:

• sedikit selada

Putting sedikit after the noun is generally not how this quantity phrase is formed.

So for basic learners, remember:

• sedikit + noun

Examples:

• sedikit nasi
• sedikit garam
• sedikit selada

Bekal is an important word here. It means something like:

• provisions
• food prepared to take somewhere
• packed meal
• lunch to bring along

So:

• untuk bekal besok means for tomorrow’s packed meal/lunch or to bring tomorrow

This is more specific than just untuk besok.

Compare:

• untuk besok = for tomorrow
• untuk bekal besok = for tomorrow’s packed food / as provisions for tomorrow

So bekal adds the idea that the sandwich is being prepared to take along later, not just made at some point tomorrow.

Yes, this is normal.

• bekal besok literally looks like tomorrow’s provisions/lunch
• a more natural English translation is for tomorrow’s lunch or for lunch tomorrow, depending on context

In Indonesian, nouns are often followed by words that narrow or describe them.

So:

• bekal besok = the provisions/lunch for tomorrow

This is a compact and natural way to express the idea.

Here, untuk means for.

So:

• untuk bekal besok = for tomorrow’s lunch/packed meal

Untuk is very common and can mean:

• for
• intended for
• in order to (in some contexts)

Examples:

• Ini untuk kamu. = This is for you.
• Saya belajar untuk ujian. = I study for the exam.
• Saya membuat sandwich untuk bekal besok. = I’m making a sandwich for tomorrow’s lunch/to take tomorrow.

Sometimes Indonesian allows shorter phrasing, but here untuk helps make the relationship clear and sounds natural.

• Saya membuat sandwich ... untuk bekal besok. = clear and natural

If you remove it:

• Saya membuat sandwich ... bekal besok.

that sounds incomplete or awkward in standard Indonesian.

So in this sentence, keep untuk.

No, it is a loanword, adapted from mayonnaise.

Indonesian often adapts foreign words to Indonesian spelling, so:

• mayonnaise → mayones

This is very common in Indonesian vocabulary. Other borrowed food words work similarly.

For learners, it is good to remember that Indonesian spelling is often more phonetic than English spelling.

Yes. Jagung means corn.

In the sentence, jagung is simply one of the sandwich ingredients.

Like many Indonesian nouns, it does not change form for singular/plural, so it can refer to corn in a general ingredient sense without extra marking.

Usually people do say sandwich, especially in urban Indonesian and modern food contexts.

There is not a very common everyday native replacement that works exactly the same way in all situations. So sandwich is perfectly natural.

In Indonesia, many food names are borrowed directly or semi-directly from other languages.

A very natural casual version would be:

• Aku bikin sandwich pakai mayones, jagung, dan sedikit selada buat bekal besok.

Changes:

• saya → aku = more casual
• membuat → bikin = more casual
• dengan → pakai = more conversational for ingredients
• untuk → buat = casual for

Your original sentence is correct and natural, just a bit more neutral/standard.

The structure is:

• Saya = subject
• membuat = verb
• sandwich = object
• dengan mayones, jagung, dan sedikit selada = ingredient/additional description
• untuk bekal besok = purpose

So the full pattern is roughly:

• Subject + Verb + Object + With-phrase + For-phrase

That makes the sentence easy to break down:

• Saya — I
• membuat sandwich — make a sandwich
• dengan ... — with ...
• untuk ... — for ...

Indonesian verbs do not usually change form for tense the way English verbs do.

So membuat by itself does not tell you whether it is:

• make
• am making
• made
• will make

Time is usually understood from context or from time words.

Here, besok means tomorrow, but it refers to bekal rather than necessarily the time of making. The sentence most naturally suggests something like:

• I’m making a sandwich ... for tomorrow’s lunch

So the action is likely happening now, but the verb form itself does not mark that directly.

You would usually add a time word or context to show the past.

For example:

• Saya membuat sandwich ... tadi pagi. = I made a sandwich ... this morning.
• Saya sudah membuat sandwich ... = I have already made a sandwich ...

The verb membuat itself stays the same. Indonesian relies heavily on context, adverbs, and helper words like sudah for completed actions.

It can mean more than just food.

Common meanings of bekal include:

• provisions
• supplies
• something you bring along
• figuratively, something that equips you for the future

Examples:

• bekal makanan = food supplies
• bekal sekolah = food/items brought for school
• pengalaman itu menjadi bekal untuk masa depan = that experience became preparation/capital for the future

In your sentence, though, bekal very naturally refers to food prepared to take along.

Yes, it is natural and correct.

It sounds fairly neutral and standard. A native speaker would understand it easily.

The only thing to keep in mind is that in very casual conversation, many speakers might choose a looser version such as:

• Saya bikin sandwich pakai mayones, jagung, dan sedikit selada buat bekal besok.

But your original sentence is absolutely good Indonesian.