Learn Hardcore Polish: Po koncercie słychać głośne oklaski. - After the concert loud applause can be heard.

The noun koncert in the locative singular is koncercie.
So po koncercie literally means after the concert (in time) or on the concert (in a very abstract sense), but in practice it is just “after the concert”.

Forms like po koncert or po koncertu are simply ungrammatical with this meaning, because they are not locative.

What exactly does słychać mean, and why isn’t there any subject like one can hear or it is heard?

Słychać is an impersonal verb form that roughly means one can hear / it is audible / it can be heard.

It doesn’t need (and normally doesn’t take) an explicit subject.
The structure słychać + [object] literally says that something is being heard, without saying who hears it.

So Po koncercie słychać głośne oklaski is best understood as After the concert, loud applause can be heard or Loud applause is heard after the concert, with no expressed subject.

How is słychać different from słyszeć and słuchać? They all look similar.

They are related but used differently:

słyszeć – to hear (a normal personal verb)
- Słyszę oklaski. – I hear applause.
słuchać – to listen to (an action you do on purpose)
- Słucham muzyki. – I am listening to music.
słychać – to be audible / to be heard (impersonal)
- Słychać oklaski. – Applause can be heard / There is the sound of applause.

In the sentence Po koncercie słychać głośne oklaski, słychać is used because we are describing a sound that is generally audible, not what a specific person is doing.

What case are głośne oklaski, and why does głośne end in -e?

With słychać, the thing that is heard is in the accusative case.

oklaski (applause) is a plural-only noun; its nominative and accusative forms are both oklaski, so you see oklaski in the accusative here.
oklaski are grammatically masculine inanimate plural, and adjectives for this gender/number in the nominative and accusative take the ending -e.

So:

głośne (loud) is masculine inanimate plural accusative, agreeing with oklaski.
Together głośne oklaski means loud applause as the object of słychać.

If English uses “can be heard”, why is there no word like móc (can) in the Polish sentence?

Polish often expresses the idea of “can be heard / is audible” directly with słychać, without any extra verb of possibility.

Słychać oklaski. – Applause can be heard. (literally more like “It is heard, applause.”)
Adding móc (można słychać oklaski) would sound unnatural here.

So słychać itself already contains the sense of “can be heard / is audible”, which is why no separate can is needed.

Why isn’t it Po koncercie są głośne oklaski instead?

You can say Po koncercie są głośne oklaski, but it sounds different:

Po koncercie są głośne oklaski. – After the concert, there is loud applause.
Focus: the existence or occurrence of applause.
Po koncercie słychać głośne oklaski. – After the concert, loud applause can be heard.
Focus: the sound of the applause, what you perceive with your ears.

The version with słychać is more about the auditory impression; with są, it is more about the fact that the applause happens.

The event is “after the concert”, so why is słychać in the present tense?

Polish often uses the present tense to talk about:

Typical / habitual situations: what usually happens after concerts.
Narrative or “live” description: describing events as if they are unfolding now.

So Po koncercie słychać głośne oklaski can mean:

Each time there is a concert, afterwards you can hear loud applause (general truth).
Or a vivid description of a specific situation: Now the concert is over, and now you can hear loud applause.

For a specific past event you could say: Po koncercie było słychać głośne oklaski. – After the concert, loud applause could be heard.

Can I change the word order? For example, can I say Głośne oklaski słychać po koncercie?

Yes, Polish word order is relatively flexible, and these versions are possible:

Po koncercie słychać głośne oklaski. – neutral, common.
Głośne oklaski słychać po koncercie. – emphasizes głośne oklaski.
Słychać głośne oklaski po koncercie. – neutral but with a bit more focus on the fact that something is audible.

The basic grammar (cases, endings) must stay the same, but the order can change to shift emphasis.

Is oklaski always plural? How do you say an applause in Polish?

Yes, oklaski is a plural-only noun (pluralia tantum) in normal modern usage.

You generally don’t use a singular like oklask in everyday speech.
Instead of an applause, Polish just says oklaski or brawa:
- Po koncercie były głośne oklaski.
- Publiczność dała mu gromkie brawa.

So to express “applause”, use oklaski or brawa, both in the plural form.

Are oklaski and brawa the same, or is there any difference?

They are very close in meaning and often interchangeable; both mean applause, clapping.

oklaski – very common, neutral.
brawa – also very common; often used in expressions like:
- gromkie brawa – thunderous applause
- zasłużone brawa – well‑deserved applause

In your sentence you could also say Po koncercie słychać głośne brawa, and it would sound natural.

How do you pronounce słychać and how is it different from słuchać?

Pronunciation (in simple terms):

słychać ≈ SWIH‑hatch
- y is like a hard i, similar to the vowel in English “myth”, but tenser and further back.
słuchać ≈ SWOO‑hatch
- u like oo in “food”.

So:

słychać (with y) = to be heard / can be heard (impersonal).
słuchać (with u) = to listen (to).

Mixing them up changes the meaning of the sentence completely.