Formulir klaim hendaknya diisi dengan lengkap.

Hendaknya means something like should, ought to, or it is advisable that.

In this sentence, it gives a polite instruction rather than a harsh command. It is common in formal writing, notices, instructions, and official language.

So compared with other words:

• hendaknya = should / ought to / preferably
• harus = must
• sebaiknya = it would be best to

Here, hendaknya sounds formal and polite.

Diisi is the passive form of isi (to fill in).

• mengisi = to fill in, to fill out (active)
• diisi = be filled in, to be filled in (passive)

The sentence focuses on the claim form, not on the person doing the action. That is why the passive is used.

Compare:

• Anda hendaknya mengisi formulir klaim dengan lengkap.
  = You should fill out the claim form completely.
  Active: focus on you

• Formulir klaim hendaknya diisi dengan lengkap.
  = The claim form should be filled out completely.
  Passive: focus on the form

This passive style is very common in instructions and official notices in Indonesian.

Yes. It is a passive sentence.

The key sign is diisi:

• di- = passive prefix
• isi = root meaning fill

So diisi literally means filled in or be filled in.

A native English speaker may think of it as similar to:

• The claim form should be completed fully.
• The claim form should be filled out completely.

Indonesian often uses the passive in formal instructions because it sounds impersonal and official.

The person is understood from context.

In Indonesian, especially in formal instructions, it is very normal not to mention you directly. The sentence simply states what should happen to the form.

So even though Anda is not written, the intended meaning is usually:

• You should fill out the claim form completely, or
• The claim form should be filled out completely

This is similar to English instruction style such as Forms must be completed in full.

Dengan lengkap means completely, fully, or in full.

Literally:

• dengan = with
• lengkap = complete, complete/full

But as a phrase, diisi dengan lengkap means:

• filled in completely
• filled out fully
• completed in full

In practice, it suggests that all required information should be entered, not left incomplete.

Both patterns can exist, but dengan lengkap is a very common and natural formal expression.

• diisi dengan lengkap = filled in completely / in full
• diisi lengkap = also understandable, but less standard in this kind of official instruction

Using dengan + adjective often turns the adjective into an adverb-like phrase.

So:

• lengkap = complete
• dengan lengkap = completely / in a complete manner

In official Indonesian, dengan lengkap sounds smoother and more idiomatic here.

Formulir klaim means claim form.

Indonesian noun phrases usually go in this order:

• main noun first
• describing noun second

So:

• formulir = form
• klaim = claim
• formulir klaim = claim form

This is the reverse of typical English order, where the describing noun often comes first.

Other examples:

• kantor pos = post office
• kartu kredit = credit card
• surat kabar = newspaper

So formulir klaim follows a very normal Indonesian pattern.

Yes, but the meaning becomes stronger.

Compare:

• Formulir klaim hendaknya diisi dengan lengkap.
  = The claim form should be filled out completely.

• Formulir klaim harus diisi dengan lengkap.
  = The claim form must be filled out completely.

So the difference is mainly tone:

• hendaknya = polite recommendation or formal instruction
• harus = obligation, stronger requirement

In many official contexts, both are possible, but hendaknya sounds less strict.

Because here di- is a prefix, not the preposition di.

In Indonesian:

• di-

  • verb = passive verb prefix
    Example: diisi, ditulis, dibaca

• di

  • place noun = preposition meaning in / at / on
    Example: di rumah, di kantor, di meja

So:

• diisi = filled in
• di isi = incorrect in this sentence

A useful rule: If di is part of a verb, write it together.
If di means location, write it separately.

Some changes are possible, but the original sentence is the most natural formal version.

Original:

• Formulir klaim hendaknya diisi dengan lengkap.

Possible alternative:

• Hendaknya formulir klaim diisi dengan lengkap.

This is still correct, but it sounds a little more marked or stylistically different. The original version is more straightforward in official writing.

A less natural version would be:

• Formulir klaim diisi hendaknya dengan lengkap.

That sounds awkward.

So yes, Indonesian word order is somewhat flexible, but not every rearrangement sounds equally natural.

It could be either, depending on context, but most naturally it is understood as singular: the claim form.

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

So formulir can mean:

• form
• forms

If the writer wants to make plurality explicit, they might say:

• formulir-formulir klaim = claim forms

But in this sentence, the most natural reading is a general instruction about a claim form or the claim form.

Yes, secara lengkap is possible, but dengan lengkap is more natural in this specific sentence.

Compare:

• diisi dengan lengkap = very common and natural
• diisi secara lengkap = understandable, somewhat more formal or abstract

Both mean roughly filled in completely, but dengan lengkap is the expression you are more likely to see on forms and instructions.

So if you are learning the standard phrase for official documents, diisi dengan lengkap is the safer choice.