Learn Hardcore Indonesian: Saya lagi mengetik laporan dan memeriksa kertas catatan. - I am typing a report and checking my paper notes.

Placed before a verb, lagi marks a progressive/ongoing action (“currently doing”). So it’s like English “am/is/are -ing.” Note that lagi can also mean “again,” but that meaning usually comes when it appears after the verb or object.

What’s the difference between lagi and sedang (and tengah)?

lagi: very common in everyday speech; informal-neutral.
sedang: neutral and a bit more formal; safe in writing and speech.
tengah: formal/literary tone (“in the middle of” doing something).
All can mark the progressive: Saya lagi/sedang/tengah mengetik laporan.

Does lagi apply to both verbs, or only to the first one?

It scopes over both coordinated verbs. Saya lagi mengetik ... dan memeriksa ... means both actions are ongoing. You don’t need to repeat lagi before the second verb.

Can I move lagi later in the sentence?

For the progressive meaning, keep lagi before the verb phrase (typically right after the subject). If you put lagi after the verb or object (e.g., Saya mengetik lagi), it means “again,” not progressive.

Why use mengetik instead of menulis?

mengetik = to type (on a keyboard).
menulis = to write (by hand) or to author/compose.
If you mean typing on a computer, mengetik laporan is the natural choice. Menulis laporan focuses on composing the report (regardless of medium).

Is memeriksa the same as mengecek or ngecek?

memeriksa: standard “to check/examine/review”; neutral/formal.
mengecek: borrowed from “check”; common and acceptable.
ngecek: very informal/colloquial.
All can work; pick based on register. For formal writing, memeriksa is safest.

Is kertas catatan the natural way to say “my notes”?

It literally means “note paper(s)” or “sheets of notes,” emphasizing the physical paper. If you mean the content “notes,” just say catatan. For a notebook, say buku catatan.
Examples:

physical sheets: memeriksa kertas catatan
the notes (content): memeriksa catatan
a sheet of note paper: selembar kertas catatan

Do I need words like “a/the” for laporan and kertas catatan?

Indonesian has no articles. Bare nouns can be “a” or “the” depending on context. To be explicit:

“a report”: sebuah laporan
“a sheet of note paper”: selembar kertas catatan
“the report/notes”: laporannya/catatannya or laporan itu/catatan itu

Why isn’t saya repeated before the second verb?

Both verbs share the same subject, so repeating saya is unnecessary. Saya lagi mengetik laporan dan memeriksa ... is normal. Repeating it (Saya ... dan saya ...) is possible but sounds heavy.

Can I drop the subject and just say Lagi mengetik laporan dan memeriksa ...?

Yes, in informal contexts and when it’s clear who the subject is. In careful or formal writing, keep saya.

Why memeriksa and not just periksa?

In statements, active transitive verbs normally take the meN- prefix: memeriksa. The bare form periksa is typical for imperatives/headlines: Tolong periksa catatan (“Please check the notes”).

How do the forms mengetik and memeriksa come from the roots?

They use the active prefix meN- with sound changes:

ketik → mengetik (initial k drops; prefix appears as meng-).
periksa → memeriksa (initial p drops; prefix appears as mem-).
Colloquially, you might hear meriksa (a shortened form of memeriksa).

Is dan the best way to show the actions happen at the same time?

Dan simply lists actions; context plus lagi/sedang implies simultaneity. If you want to stress “while,” use sambil:
Saya lagi mengetik laporan sambil memeriksa catatan.

Can I use aku or other pronouns instead of saya?

Yes:

aku: casual/intimate.
saya: neutral/polite.
gue/gua (Jakarta slang): very informal.
All can combine with lagi/sedang appropriately.

Is it okay to say something like Saya lagi ketik laporan dan cek catatan?

In standard Indonesian, keep the meN- forms: mengetik and memeriksa/mengecek. In casual speech, people often use colloquial forms: Aku lagi ngetik laporan dan ngecek catatan.

How would I say this in the passive?

To foreground the objects: Laporan sedang diketik dan catatan sedang diperiksa (oleh saya). The agent (oleh saya) is optional.

Do I need to mark plurals for “papers/notes”?

Not unless you want to emphasize plurality. Indonesian leaves number unmarked. To force plural, use reduplication or a quantifier: kertas-kertas catatan, beberapa lembar kertas catatan, beberapa catatan.

What about mengetikkan—is that different from mengetik?

Yes. mengetik = to type something. mengetikkan often means to type something for someone or to type something into a field/form:

Saya mengetik laporan. (I type the report.)
Saya mengetikkan data ke formulir. (I type the data into the form.)