Električni aparat i elektronska oprema idu na sakupljačko mesto.

Because the subject is made of two parts joined by i = and:

Električni aparat i elektronska oprema

Even though oprema is grammatically singular, the whole subject is a compound subject, so Serbian uses the plural verb idu = go.

Compare:

• Elektronska oprema ide... = The electronic equipment goes...
• Električni aparat i elektronska oprema idu... = The electrical appliance and the electronic equipment go...

Serbian often uses the singular in general statements, labels, instructions, or category names. So električni aparat can mean an electrical appliance in a generic sense, not necessarily one specific appliance.

In a different context, you could also see:

• Električni aparati i elektronska oprema... = Electrical appliances and electronic equipment...

So the singular here is not strange; it can sound like a category label.

Yes, and Serbian works similarly here. Oprema is usually an uncountable or collective noun, like English equipment. It is grammatically singular even when it refers to multiple items.

So:

• oprema je nova = the equipment is new
• not normally opreme su... when you mean pieces of equipment

That is why the sentence uses elektronska oprema, not a plural form.

They are related but not the same:

• električni = electrical, powered by or related to electricity
• elektronski / elektronska / elektronsko = electronic

So:

• električni aparat = electrical appliance/device
• elektronska oprema = electronic equipment

Also notice the form change:

• elektronska is the feminine singular form, because oprema is feminine.

Because adjectives in Serbian must agree with the noun they describe in gender, number, and case.

Here:

• aparat is masculine singular, so: električni aparat
• oprema is feminine singular, so: elektronska oprema
• mesto is neuter singular, so: sakupljačko mesto

This agreement is one of the most important features of Serbian grammar.

Serbian uses both na and u for location and motion, but the choice depends on how the destination is viewed.

Here mesto means place/spot/point, and Serbian often uses na with places understood as points, stations, sites, surfaces, or designated locations.

So:

• ići na mesto = go to a place/spot
• ići u zgradu = go into a building

In this sentence, sakupljačko mesto is understood as a collection point or collection site, so na sounds natural.

It is the accusative, because the phrase shows motion toward a destination.

A useful rule:

• na
  • accusative = motion toward something
• na
  • locative = location at/on something

So:

• Idem na sakupljačko mesto. = I am going to the collection point.
• Ja sam na sakupljačkom mestu. = I am at the collection point.

Notice that mesto looks the same in nominative and accusative singular because it is a neuter noun.

Yes. Idu is the 3rd person plural present tense of ići = to go.

This verb is somewhat irregular, so its forms do not all look very close to the infinitive:

• ja idem = I go / I am going
• ti ideš
• on/ona/ono ide
• mi idemo
• vi idete
• oni/one/ona idu

So idu simply means they go / are going.

Serbian does not have articles like a/an and the.

So:

• električni aparat can mean an electrical appliance or the electrical appliance
• elektronska oprema can mean electronic equipment or the electronic equipment

The exact meaning comes from context. In signs, instructions, and category labels, Serbian often leaves this unstated.

Yes. Serbian word order is more flexible than English, although not completely free.

The original sentence is neutral:

• Električni aparat i elektronska oprema idu na sakupljačko mesto.

You could also say:

• Na sakupljačko mesto idu električni aparat i elektronska oprema.

That version emphasizes the destination a bit more.

Even when the word order changes, the case endings and verb agreement help show what belongs together.

It is an adjective related to collecting or collection, from the verb sakupljati = to collect.

So:

• sakupljačko mesto = collection point / collection site

The ending -o is there because mesto is neuter singular.

Depending on region or style, you may also encounter other expressions for similar ideas, but in this sentence sakupljačko mesto simply means a designated place where items are collected.

Then Serbian would normally use na + locative, and the verb might describe being rather than going.

Compare:

• Električni aparat i elektronska oprema idu na sakupljačko mesto.
  = They go to the collection point.

• Električni aparat i elektronska oprema su na sakupljačkom mestu.
  = They are at the collection point.

Notice the change:

• sakupljačko mesto → accusative after motion
• sakupljačkom mestu → locative after location

This is a very common Serbian pattern.