Lelang dan undian membutuhkan izin keramaian.

Lelang means auction.

It refers to a sale where people bid against each other, and the item usually goes to the highest bidder. In official or legal contexts, lelang is the standard word for auction.

Undian usually means a drawing, lottery, or raffle, depending on context.

In this sentence, it refers to some kind of chance-based drawing or prize draw. A native English speaker should note that undian is broader than any one single English word, so the best translation depends on the situation.

Membutuhkan is the verb form meaning to need or to require.

It comes from the root butuh (need) with the prefix mem- and suffix -kan, which makes it sound more like a full transitive verb in standard Indonesian.

So:

• butuh = need / needy / to need in casual speech
• membutuhkan = to need / to require, more formal and standard

In an official sentence like this, membutuhkan sounds more natural than the shorter, more conversational butuh.

Izin keramaian means something like a public gathering permit or a crowd permit.

Breaking it down:

• izin = permission, permit
• keramaian = crowd, festivity, public gathering, busy public activity

So this is not just any kind of permission. It refers to official permission from authorities for an event or activity that may attract people or involve public activity.

A learner might be tempted to translate keramaian literally as noise or liveliness, but in this phrase it refers more to a public crowd/event situation.

Indonesian does not normally use articles like a, an, or the.

So:

• lelang can mean an auction, the auction, or just auction
• izin keramaian can mean a public gathering permit or the required permit, depending on context

You have to get that information from the situation, not from an article.

In Indonesian, nouns usually do not change form for singular vs. plural the way they do in English.

So lelang can mean:

• auction
• auctions

and undian can mean:

• drawing / lottery
• drawings / lotteries

In this sentence, the meaning is general: auctions and lotteries/drawings. Indonesian often leaves plurality unmarked when it is already clear from context.

The structure is:

• Lelang dan undian = subject
• membutuhkan = verb
• izin keramaian = object

So the pattern is:

Subject + Verb + Object

More specifically:

• lelang dan undian = auctions and lotteries/drawings
• membutuhkan = require
• izin keramaian = a public gathering permit

This is a very common and straightforward Indonesian sentence structure.

Indonesian verbs do not change form based on whether the subject is singular or plural.

In English, we say:

• The auction requires
• The auctions require

But in Indonesian, the verb stays the same:

• lelang membutuhkan
• lelang dan undian membutuhkan

So there is no verb agreement like in English.

Yes, it sounds fairly formal and administrative.

Clues that make it sound formal:

• membutuhkan instead of casual butuh
• izin keramaian, which is an official/legal expression
• the general, rule-like wording

This sounds like something you might see in regulations, notices, or official information.

Yes, but with slightly different style or structure.

Possible alternatives:

• Lelang dan undian memerlukan izin keramaian.
• Lelang dan undian perlu izin keramaian.

Differences:

• membutuhkan = need, require
• memerlukan = require, need; also formal
• perlu = need to / need; often slightly simpler and sometimes less formal-sounding

All are understandable, but membutuhkan and memerlukan fit official language especially well.

Dan simply means and, joining the two nouns lelang and undian.

So:

• lelang dan undian = auctions and lotteries/drawings

Other connectors are possible in different styles, for example:

• lelang maupun undian = both auctions and lotteries/drawings
• lelang atau undian = auction or lottery/drawing

But in your sentence, dan is the normal and direct choice.

Yes.

• ramai = crowded, lively, busy
• keramaian = crowd, bustle, public festivity, busy public situation

The prefix-suffix pattern ke- -an often turns an adjective or root into a noun.

So ramai becomes keramaian, which refers to the state or phenomenon of public busyness/crowds. In izin keramaian, that noun becomes part of a fixed phrase meaning an official permit for a public event or crowd-related activity.

It is understandable in conversation, but it sounds more like official wording than casual speech.

In everyday speech, someone might say something like:

• Kalau ada lelang atau undian, perlu izin.
• Lelang dan undian harus pakai izin keramaian.

Those versions sound more conversational. The original sentence is natural, but it feels like something written in a notice, regulation, or announcement.