Saya tadi membaca ulang proposal di perpustakaan.

Saya is the more neutral and polite word for I. It works well in formal or standard Indonesian, and in writing.

Aku also means I, but it is more casual and personal. You would use aku with friends, family, or in informal contexts.

So in a sentence with proposal and perpustakaan, saya sounds very natural.

Tadi refers to earlier today or a little while ago. It points to a time in the recent past.

So it is different from:

• kemarin = yesterday
• dulu = in the past / long ago / before
• barusan = just now

In this sentence, tadi tells you the action happened recently, not at some unspecified past time.

Indonesian word order is flexible, but this placement is very normal:

Saya tadi membaca ulang proposal di perpustakaan.

It feels like:

• Saya = topic / subject
• tadi = time
• membaca ulang = action
• proposal = object
• di perpustakaan = place

You could also hear:

• Tadi saya membaca ulang proposal di perpustakaan.

That version puts more focus on the time expression tadi. Both are natural.

Membaca is the verb with the meN- prefix, which is very common in standard Indonesian for active verbs.

• baca = read / the root
• membaca = to read

In careful, standard sentences, membaca is preferred.

Baca by itself is very common in casual speech, for example:

• Saya tadi baca ulang proposal di perpustakaan.

That sounds more informal but is very natural in conversation.

Membaca ulang means to read again or to reread.

Here, ulang adds the idea of repetition. It often works like again or re- in English.

Examples:

• menulis ulang = rewrite
• membuka ulang = reopen
• membaca ulang = reread

So this is not just read, but specifically read again.

Usually, with this meaning, ulang comes after the verb:

• membaca ulang proposal

That is the normal pattern.

You may also hear mengulang in other structures, but that usually means to repeat something rather than simply to do again in the same way.

Compare:

• membaca ulang proposal = reread the proposal
• mengulang bacaan = repeat the reading / go over the reading again

For this sentence, membaca ulang is the most natural choice.

Indonesian does not have articles like a, an, or the.

So proposal can mean:

• a proposal
• the proposal

The exact meaning depends on context.

If the context already makes it clear which proposal is meant, English may translate it as the proposal. But Indonesian itself does not need a separate word for that.

By itself, proposal is usually understood as singular in this sentence, but Indonesian nouns do not always mark singular vs. plural clearly.

If you wanted to make it clearly plural, you might say:

• proposal-proposal

However, Indonesian often leaves number unmarked unless it is important.

So in context, proposal most likely means the proposal or a proposal, singular.

Because di shows location, while ke shows movement toward a destination.

• di perpustakaan = at/in the library
• ke perpustakaan = to the library

This sentence describes where the rereading happened, not where the speaker went. So di perpustakaan is correct.

No. This is an important distinction.

In di perpustakaan, di is a preposition meaning in/at, so it is written separately from the following word.

• di perpustakaan = in the library

But in passive verbs, di- is a prefix, so it is written attached to the verb.

• dibaca = is read / was read
• ditulis = is written / was written

So:

• di perpustakaan = separate
• dibaca = attached

It strongly suggests a completed past event, especially because of tadi, but Indonesian does not mark tense the way English does.

The sentence gives past time through tadi, not through a special past verb form.

So membaca ulang itself does not mean past; tadi makes it clear that the action happened earlier. In many contexts, the sentence is understood as a completed event.

If you wanted to emphasize completion even more, Indonesian might add words like:

• sudah = already
• telah = already / has, have

For example:

• Saya tadi sudah membaca ulang proposal di perpustakaan.

Yes, that is possible. Indonesian allows some flexibility in word order.

These all sound natural, though the emphasis changes slightly:

• Saya tadi membaca ulang proposal di perpustakaan.
• Tadi saya membaca ulang proposal di perpustakaan.
• Saya membaca ulang proposal tadi di perpustakaan.

The original version is very smooth and neutral. Putting tadi earlier often helps set the time frame sooner.

It is mostly neutral to somewhat formal.

Why?

• saya is neutral/polite
• membaca is the full standard verb form
• the sentence structure is clear and standard

A more casual spoken version might be:

• Aku tadi baca ulang proposal di perpustakaan.

That sounds more conversational. The original sentence is perfectly natural in standard Indonesian.

In normal interpretation, di perpustakaan describes where the reading happened, not which proposal.

So the sentence is understood as:

• the speaker reread the proposal
• the rereading took place in the library

If you wanted to make in the library describe the noun proposal, that would be unusual and unclear here. Indonesian readers will naturally connect di perpustakaan with the action membaca ulang.

A casual spoken version could be:

• Aku tadi baca ulang proposal di perpustakaan.

Changes:

• saya → aku for casual I
• membaca → baca in informal speech

But the original sentence is still completely natural, especially in standard spoken Indonesian, writing, or polite conversation.