Saya membersihkan remah kue dengan lap.

Bersih means clean as an adjective: The table is clean.

Membersihkan is the verb to clean something. It is built from:

• bersih = clean
• meN- = a verbal prefix
• -kan = a suffix that often helps make a transitive verb

So membersihkan means to make something clean / to clean.

That is why it fits in this sentence:
Saya membersihkan remah kue... = I clean / cleaned the cake crumbs...

In Indonesian, noun + noun combinations often do the job that English sometimes expresses with of.

So:

• remah kue = cake crumbs, cookie crumbs, or crumbs of cake/cookies

You do not need a separate word meaning of here. The second noun, kue, simply describes what kind of crumbs they are.

This pattern is very common in Indonesian.

Kue is a broad word in Indonesian. Depending on context, it can refer to:

• cake
• cookie
• pastry
• sweet snack

So remah kue could mean cake crumbs or cookie crumbs, depending on the situation.

If your translation already gives one specific meaning, that is just the context-specific choice.

Indonesian usually does not have to mark singular vs. plural the way English does.

So remah kue can mean:

• a cake crumb
• cake crumbs

Context usually makes it clear.

If you want to make the plural idea more explicit, you can say:

• remah-remah kue = cake crumbs / cookie crumbs

But in normal Indonesian, leaving the noun unmarked is very common.

Here dengan means with in the sense of using an instrument or tool.

So:

• dengan lap = with a cloth / using a cloth

This is different from English with meaning together with someone.
In this sentence, dengan introduces the tool used for cleaning.

Here lap is a noun meaning cloth, rag, or cleaning cloth.

So dengan lap means with a cloth.

A related verb is mengelap, which means to wipe.

So:

• lap = a cloth
• mengelap = to wipe

Indonesian does not use articles like English a, an, and the in the same way.

So:

• remah kue can mean a cake crumb, the cake crumbs, or just cake crumbs
• lap can mean a cloth or the cloth

The listener figures it out from context.

This is one of the biggest differences from English.

Yes. The sentence follows a very common Indonesian order:

• Saya = subject
• membersihkan = verb
• remah kue = object
• dengan lap = prepositional phrase telling you the tool

So the structure is:

Subject + Verb + Object + Tool/Instrument

That is very natural in Indonesian.

Yes, in many situations.

• Saya is neutral, polite, and common in standard Indonesian.
• Aku is more casual and personal.

So:

• Saya membersihkan remah kue dengan lap sounds neutral/polite.
• Aku membersihkan remah kue dengan lap sounds more casual.

Both are grammatically fine. The choice depends on the situation and tone.

Yes, it is understandable and natural enough.

It means that you cleaned up the crumbs using a cloth.

However, in real life, Indonesians might sometimes be more specific depending on what they want to emphasize:

• Saya membersihkan remah kue dari meja dengan lap = I cleaned cake crumbs off the table with a cloth
• Saya membersihkan meja dari remah kue dengan lap = I cleaned the table of cake crumbs with a cloth

So the original sentence is fine, but if you want to mention the surface being cleaned, Indonesian often makes that explicit.