Learn Hardcore Indonesian: Saya sarapan roti dengan mentega. - I have bread with butter for breakfast.

No. In Indonesian, sarapan already functions as a verb meaning “to have/eat breakfast.” So Saya sarapan roti dengan mentega is natural. Saying Saya makan sarapan is redundant and sounds odd. You can, however, use an alternative structure with “makan” plus a purpose phrase:

Saya makan roti dengan mentega untuk sarapan. “Bersarapan” exists but sounds formal/literary; everyday speech uses sarapan.

What tense is this? How do I show past, present, or future?

Indonesian doesn’t mark tense on the verb. Add time words or aspect markers:

Past (earlier today): Tadi pagi saya sarapan roti dengan mentega.
Completed: Saya sudah sarapan roti dengan mentega.
Progressive/now: Saya sedang sarapan roti dengan mentega. / Colloquial: Aku lagi sarapan roti dengan mentega.
Future: Besok pagi saya akan sarapan roti dengan mentega.

Is “sarapan” a verb or a noun?

Both, depending on context.

Verb: Saya sarapan roti dengan mentega.
Noun: Sarapan saya roti dengan mentega. (You can add or omit adalah; everyday speech often omits it.)

Can I drop the subject “Saya”?

Yes, if the context already makes the subject clear (very common in conversation or notes):

(Saya) sarapan roti dengan mentega.
Replying to “Lagi apa?”: (Lagi) sarapan. In careful/formal writing, keep the subject.

Is “dengan” here the same as “and”? How does it differ from “pakai” or “sama”?

dengan = “with,” neutral/standard. roti dengan mentega suggests bread served/topped with butter.
pakai = “using/with,” very common colloquial: roti pakai mentega.
sama = colloquial “with”: roti sama mentega (informal).
dan = “and” (listing two separate items): roti dan mentega = bread and butter (as two things), not necessarily one on the other.

Does “roti dengan mentega” mean the butter is on the bread?

Yes, it normally implies bread served with butter on it. If you literally mean two separate items listed, say roti dan mentega.

How do I specify quantity, like “a slice of bread” or “two slices”?

Use classifiers/measure words:

One slice/piece: sepotong roti (very common); also selembar roti is used.
Two slices: dua potong roti / dua lembar roti.
A loaf (plain sliced bread): sebuah roti tawar; packaged loaf: sebungkus roti tawar. Example: Saya sarapan dua potong roti dengan mentega.

How do I add frequency or habitual meaning (e.g., “I usually…” “every morning”)?

Add an adverb or time phrase:

Saya biasanya sarapan roti dengan mentega.
Setiap pagi saya sarapan roti dengan mentega.
Saya sering/jarang/kadang-kadang sarapan roti dengan mentega.

How do I negate this? What about “not yet”?

General negation: tidak.
- Saya tidak sarapan roti dengan mentega.
“Not yet”: belum, implying you might later.
- Saya belum sarapan.
Past specific: Tadi pagi saya tidak sarapan roti dengan mentega.

Is there another natural way to say the same idea?

Yes:

Saya sarapan roti dengan mentega. (using “sarapan” as a verb)
Saya makan roti dengan mentega untuk sarapan. (using “makan” + purpose phrase) Avoid: Saya makan sarapan… (redundant).

Can I switch pronouns for different levels of formality?

Yes:

Neutral/polite: Saya sarapan roti dengan mentega.
Informal to friends: Aku sarapan roti dengan mentega.
Jakarta slang: Gue sarapan roti dengan mentega. For “we”: Kita sarapan… (inclusive) vs Kami sarapan… (exclusive).

What’s the difference between “mentega” and “margarin”?

mentega = butter (dairy, from cream). You may hear mentega asin/tawar (salted/unsalted).
margarin = margarine (plant-based spread). Example: Saya sarapan roti dengan margarin.

How do I say “toast with butter”?

Use roti bakar (very common) or roti panggang:

Saya sarapan roti bakar dengan mentega.
Aku sarapan roti panggang pakai mentega.

Do I need “a/the” before “roti” or “mentega”?

Indonesian has no articles. roti and mentega are neutral for definiteness and number. Add quantity if needed:

sepotong roti, dua potong roti, sedikit mentega.