Kad god prikupite opasan otpad, skladištenje počinje.

Kad god means whenever or every time that. It introduces a repeated or general situation.

• Kad = when
• Kad god = whenever / any time that

So:

• Kad dođeš, javi se. = When you come, let me know.
• Kad god dođeš, javi se. = Whenever you come, let me know.

In your sentence, kad god shows that this is a rule or repeated situation, not one single event.

Prikupite is the present tense form of the verb prikupiti.

Here it is:

• infinitive: prikupiti = to collect / gather
• present tense, 2nd person plural: (vi) prikupite = you collect

So grammatically it means you collect.

However, in Serbian, this form can refer to:

• you all collect (plural you)
• you collect (formal singular you)

Which one is meant depends on context.

Because Serbian often uses the present tense after words like kad, kad god, ako, and similar conjunctions, especially for general truths, instructions, or repeated situations.

So even though English may suggest a future-like meaning, Serbian normally keeps the present:

• Kad god prikupite opasan otpad, skladištenje počinje. = Whenever you collect hazardous waste, storage begins.

This sounds natural in Serbian because it describes a regular rule or procedure.

In Serbian, subject pronouns are often omitted because the verb ending already shows who the subject is.

Here:

• prikupite already tells us the subject is vi = you (plural/formal)

So Serbian does not need to say vi prikupite unless the speaker wants emphasis or contrast.

Compare:

• Prikupite otpad. = You collect the waste.
• Vi prikupite otpad. = You collect the waste (more explicit or emphatic)

Opasan otpad means hazardous waste.

The noun is:

• otpad = waste

The adjective is:

• opasan = dangerous / hazardous

The adjective must agree with the noun in gender, number, and case.

Here, otpad is:

• masculine
• singular
• inanimate

Because it is the direct object of prikupite, it is in the accusative case. But for masculine inanimate nouns, the accusative looks the same as the nominative.

So:

• nominative: opasan otpad
• accusative: opasan otpad

That is why the phrase stays in exactly that form.

Yes. Prikupiti is a perfective verb, while skupljati is usually imperfective.

Very roughly:

• prikupiti = to collect up / gather completely
• skupljati = to be collecting / collect repeatedly / collect over time

In a sentence like this, prikupite suggests that the waste has been gathered as a completed step. Then the next stage begins:

• first: the waste is collected
• then: storage begins

So prikupite fits well if the meaning is once you have collected it / whenever collection is completed.

Skladištenje is a verbal noun. It means storage or the storing process.

It comes from the verb skladištiti = to store.

So instead of saying something like:

• ...otpad se skladišti. = ...the waste is stored.

the sentence says:

• skladištenje počinje = storage begins

This style is very common in formal, technical, legal, and instructional Serbian. It sounds procedural and impersonal, which fits topics like waste handling.

Počinje is the present tense of the imperfective verb počinjati/počinjati? In standard use, it is from počinjati / početi as the present form commonly used with početi-type meaning in modern Serbian: počinje = begins / is beginning.

In this sentence, počinje works well because it states a general process:

• storage begins

Using the present tense here makes the sentence sound like a rule or standard procedure.

A form like počne would usually appear in different constructions, often after da or in more specific contexts. In this sentence, počinje is the normal choice.

Because the sentence starts with a subordinate clause:

• Kad god prikupite opasan otpad = dependent clause
• skladištenje počinje = main clause

In Serbian, when this kind of clause comes first, it is normally separated from the main clause by a comma.

So the structure is:

• Kad god ... , ...

This is very similar to English:

• Whenever you collect hazardous waste, storage begins.

Yes. Serbian uses the same 2nd person plural verb form for:

1. plural you
2. formal singular you

So prikupite can mean:

• you all collect
• you collect (speaking politely to one person)

Without more context, both are grammatically possible.

Yes, Serbian word order is fairly flexible, though not completely free.

The given sentence is natural and clear:

• Kad god prikupite opasan otpad, skladištenje počinje.

You could also put the main clause first:

• Skladištenje počinje kad god prikupite opasan otpad.

That still makes sense, but the original version emphasizes the condition or trigger first, which is especially common in instructions and regulations.