Навесной замок лежит рядом с упаковочным материалом.

Because рядом с requires the instrumental case in Russian.

• упаковочный материал = nominative
• с упаковочным материалом = instrumental

So after рядом с (next to / beside), the noun changes form:

• материал → материалом
• упаковочный → упаковочным

This is a very common pattern:

• рядом с домом = next to the house
• рядом с машиной = next to the car
• рядом с упаковочным материалом = next to the packaging material

Because the adjective has to agree with the noun in case, gender, and number.

Here:

• материал is masculine singular
• after рядом с, it must be in the instrumental
• so the adjective also takes the masculine/neuter singular instrumental ending: -ым / -им

That gives:

• упаковочный материал → nominative
• упаковочным материалом → instrumental

So both words change together.

Замок means lock, and навесной замок means a padlock.

Literally, навесной comes from the idea of something hung on or attached externally, so навесной замок is the standard Russian term for a padlock.

So although you may understand the sentence from the translation, it is useful to know that:

• замок by itself can mean lock
• навесной замок specifically means padlock

Russian often chooses different verbs depending on an object's position.

• лежать = to lie, to be lying
• стоять = to stand
• сидеть = to sit
• находиться = to be located

Here, лежит suggests the padlock is lying somewhere, probably on a surface, rather than standing upright or just being abstractly located.

So:

• Навесной замок лежит... = The padlock is lying...
• Навесной замок находится... = The padlock is located...

Both can be possible, but лежит is more physical and natural if the object is resting on something.

Yes, you could, but the nuance is slightly different.

• лежит focuses on the object's physical position: it is lying there.
• находится is more neutral and simply means is located.

So:

• Навесной замок лежит рядом с упаковочным материалом.
  = The padlock is lying next to the packaging material.
• Навесной замок находится рядом с упаковочным материалом.
  = The padlock is located next to the packaging material.

If you are describing a visible scene, лежит often sounds more natural.

Russian has no articles.

So Навесной замок can mean:

• a padlock
• the padlock

The exact meaning depends on context.

Likewise, упаковочный материал can mean:

• packaging material
• the packaging material
• sometimes even some packaging material, depending on context

Russian speakers understand definiteness from the situation, not from articles.

It is singular in Russian:

• материал = material

In both Russian and English, words like material can be mass nouns, meaning they refer to substance or stuff rather than countable individual items.

So упаковочный материал means something like:

• packaging material
• packing material

It does not necessarily mean only one piece. It can refer to packing substance in general, like foam, paper, bubble wrap, and so on.

Yes. Russian word order is more flexible than English because grammatical endings show the relationships between words.

The neutral version here is:

• Навесной замок лежит рядом с упаковочным материалом.

But other orders are possible, for example:

• Рядом с упаковочным материалом лежит навесной замок.
• Навесной замок рядом с упаковочным материалом лежит.

These may sound different in emphasis:

• starting with рядом с упаковочным материалом emphasizes the location
• starting with навесной замок emphasizes the object

So word order in Russian often affects focus rather than basic grammatical meaning.

Because замок is one of those Russian words that can mean two different things:

• за́мок = castle
• замо́к = lock

The difference is in stress.

In your sentence, the meaning is clearly lock, especially because of навесной. A навесной замок can only mean padlock, not anything related to a castle.

So context usually makes it clear, even if stress is not marked in normal writing.

Навесной замок is in the nominative case because it is the subject of the sentence.

It is the thing that is doing the action of лежит.

So:

• Навесной замок = nominative subject
• лежит = verb
• рядом с упаковочным материалом = prepositional phrase with instrumental after с

Only the noun phrase after рядом с changes case here. The subject stays in the nominative.

A rough pronunciation guide is:

nuh-vees-NOY zuh-MOK lyi-ZHEET RYAH-duhm s oo-puh-KOH-vuhch-nïm muh-tee-RYAH-luhm

A few useful notes:

• лежит has stress on the second syllable: лежи́т
• рядом has stress on the first syllable: ря́дом
• материалом has stress on а: материа́лом
• замок meaning lock is замо́к
• замок meaning castle would be за́мок

If you want to sound more natural, paying attention to stress is especially important in Russian.

Yes, but the meaning shifts slightly.

• рядом с = next to, right beside
• около = near, by

So:

• рядом с упаковочным материалом suggests the padlock is right next to the packaging material
• около упаковочного материала is a little broader and can mean simply near it

Also note the grammar difference:

• рядом с
  • instrumental
• около
  • genitive

So you would say:

• рядом с упаковочным материалом
• около упаковочного материала

In this expression, рядом normally combines with с to mean next to / beside:

• рядом с домом
• рядом с машиной
• рядом с упаковочным материалом

Although рядом by itself means something like nearby, when you specify what something is next to, Russian normally uses рядом с + instrumental.

So the full structure is:

рядом с + noun in instrumental case