Kuulitko yleisön viheltävän viimeisen laulun jälkeen?

Kuulitko is made of:

• kuuli- = the past stem of kuulla (to hear)
• -t = you (2nd person singular)
• -ko = the yes/no question particle

So kuulitko means did you hear?

In Finnish, the question particle is attached directly to the word, so it is written as one word, not separately.

Here yleisön is in the genitive, but not because of possession.

After verbs of perception like kuulla (to hear) and nähdä (to see), Finnish often uses a pattern like:

• kuulla jonkun tekevän jotain
• hear someone doing something

So in yleisön viheltävän:

• yleisön = the audience as the doer of the action
• viheltävän = whistling / booing

So the idea is hear the audience whistling.

Because this sentence uses a special structure after kuulla.

The pattern is:

• kuulla jonkun tekevän
• literally something like hear someone doing

So viheltävän is the form used in that pattern. It comes from viheltää and is the -van / -vän participle form.

Compare:

• Kuulin lapsen itkevän. = I heard the child crying.
• Näin hänen juoksevan. = I saw him/her running.

So yleisön viheltävän means the audience whistling.

Yes. It is very common in standard Finnish, especially with verbs like:

• kuulla = hear
• nähdä = see
• tuntea = feel
• sometimes also verbs of knowing or saying in more formal styles

For an English speaker, it is useful to learn it as a chunk:

• kuulla jonkun tekevän jotain
• nähdä jonkun tekevän jotain

It often corresponds to English hear/see someone doing something.

Yes. In everyday spoken Finnish, people often use a kun clause instead:

• Kuulitko kun yleisö vihelsi viimeisen laulun jälkeen?

That is very natural in speech.

You could also say:

• Kuulitko, että yleisö vihelsi viimeisen laulun jälkeen?

But that version can sound more like Did you hear that the audience booed/whistled... ?, meaning you heard the information, not necessarily the actual sound itself.

So the original sentence more strongly suggests direct perception.

Because jälkeen (after) is a postposition in Finnish.

That means the noun phrase comes before it, and that noun phrase is usually in the genitive:

• laulun jälkeen = after the song
• esityksen jälkeen = after the performance

So:

• viimeisen laulun jälkeen = after the last song

Also, the adjective agrees with the noun:

• viimeinen laulu = the last song
• viimeisen laulun = genitive form

It can mean either, depending on context.

Basic meaning:

• viheltää = to whistle

But with an audience, it often implies disapproval:

• whistle at someone
• boo / catcall / whistle disapprovingly

So in this sentence, it probably means something like the audience was booing or whistling disapprovingly, unless the context makes literal whistling more likely.

Grammatically, yleisö is singular.

It is a collective noun, like English audience. Even though it refers to many people, Finnish treats it as a singular noun:

• yleisö on hiljaa = the audience is quiet
• yleisö taputti = the audience applauded

So yleisön here is genitive singular.

The given order is the most neutral one for this yes/no question:

• Kuulitko yleisön viheltävän viimeisen laulun jälkeen?

But Finnish word order can change for emphasis.

For example:

• Yleisönkö kuulit viheltävän viimeisen laulun jälkeen?
  = Was it the audience that you heard whistling after the last song?

So the basic meaning can stay similar, but the focus changes. In the original sentence, nothing is especially contrastive; it is just a neutral question.

In Finnish yes/no questions, -ko/-kö is attached to the element being put in focus.

In a neutral question, it usually attaches to the finite verb:

• Kuulitko ... ? = Did you hear ... ?

But it can attach to another word if that is what you want to emphasize:

• Yleisönkö kuulit ... ? = Was it the audience that you heard ... ?
• Viimeisenkö laulun jälkeen kuulit ... ? = Was it after the last song that you heard ... ?

So in your sentence, attaching -ko to kuulit makes it a normal, neutral yes/no question.