Паспарту лежит под антибликовым стеклом.

Паспарту is an indeclinable noun in Russian. That means its form stays the same in all cases.

In this sentence, it is the subject, so it is functioning as nominative singular, but the word still looks exactly the same: паспарту.

This is common with some borrowed words in Russian.

It is in the instrumental case.

That happens because the preposition под can take different cases:

• instrumental for location: under
• accusative for motion toward/under something

Here the mat is already located under the glass, so Russian uses под + instrumental:

• под антибликовым стеклом = under anti-glare glass

Because Russian makes a clear distinction between location and movement.

• лежит под стеклом = it is lying under the glass
• положить под стекло = to put it under the glass

So:

• под + instrumental = where something is
• под + accusative = where something is going

That is a very common pattern with Russian prepositions.

Because it has to agree with стеклом in:

• gender: neuter
• number: singular
• case: instrumental

The dictionary form is антибликовое стекло.

When you put стекло into the instrumental singular, it becomes стеклом, and the adjective changes with it:

• антибликовое стекло
• антибликовым стеклом

So the ending -ым shows instrumental singular for this adjective.

Стекло is a neuter noun, and in the instrumental singular it becomes стеклом.

So the pattern is:

• nominative: стекло
• instrumental: стеклом

This is a normal case ending for many neuter nouns.

Russian often uses more specific verbs of position where English would simply use is.

Лежать means to lie or to be lying. It is used for things that are thought of as being in a horizontal position or simply resting somewhere.

So Паспарту лежит под антибликовым стеклом is very natural Russian.

English might prefer The mat is under anti-glare glass, but Russian often prefers a verb like:

• лежать = lie
• стоять = stand
• висеть = hang

Yes, лежит is present tense, third person singular.

Its infinitive is лежать.

Here is the basic pattern:

• я лежу
• ты лежишь
• он / она / оно лежит
• мы лежим
• вы лежите
• они лежат

In this sentence, паспарту is singular, so the verb is лежит.

The subject is паспарту.

You can tell because:

• it is in the nominative
• the verb лежит is singular and agrees with it

The phrase под антибликовым стеклом is a prepositional phrase telling you where it is located.

So the sentence breaks down like this:

• Паспарту = subject
• лежит = verb
• под антибликовым стеклом = location

Yes. Russian word order is fairly flexible.

The neutral order here is:

• Паспарту лежит под антибликовым стеклом.

But you could also say:

• Под антибликовым стеклом лежит паспарту.

That version puts more focus on the location first.

The meaning stays basically the same, but the emphasis changes.

Yes. It is built in a very Russian way, even though the parts are international.

It comes from:

• анти- = anti-
• блик = glare, light reflection
• -ов- / -овый = adjective-forming pattern

So антибликовый means anti-glare or non-reflective.

Russian often forms technical or descriptive adjectives like this.

Then Russian would normally use a verb of motion/placement and под + accusative.

For example:

• Паспарту положили под антибликовое стекло.
  = They put the mat under anti-glare glass.

Compare that with your sentence:

• Паспарту лежит под антибликовым стеклом.
  = The mat is lying under anti-glare glass.

So the case change helps show the difference between:

• resulting location
• movement into that location

The stress is on the last syllable:

• паспарту́

This word is borrowed from French, and the final stressed -у́ is important.

A rough English approximation would be something like pahs-par-TOO, but with Russian pronunciation.