На столе лежит розовая папка.

Because на can take different cases depending on the meaning.

• на стол = onto the table → direction/motion toward a surface
• на столе = on the table → location

Here the folder is already there, so Russian uses the prepositional case: стол → на столе.

Столе is in the prepositional case.

With на, the prepositional case is commonly used when you are talking about a place where something is located:

• на столе = on the table
• на полке = on the shelf
• на полу = on the floor

So in this sentence, на столе tells you the location.

Russian often does not use a present-tense equivalent of is/am/are in the same way English does.

Instead of saying something like The pink folder is on the table, Russian very naturally says something more like:

• On the table lies a pink folder

Here, лежит is the verb and literally means lies / is lying.

So the sentence sounds natural in Russian because the verb describes the object's position rather than using a general is.

Usually, yes—that is the idea.

Russian often chooses verbs based on the physical position of an object:

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

A folder is thought of as a flat object, so лежит is very natural.

For comparison:

• На столе лежит книга. = A book is lying on the table.
• На столе стоит чашка. = A cup is standing on the table.
• На стене висит картина. = A picture is hanging on the wall.

Sometimes learners expect a neutral verb like to be, but Russian often prefers this more concrete way of describing where something is.

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

Here:

• папка is feminine
• it is singular
• it is in the nominative case (because it is the subject)

So the adjective розовый changes to the feminine nominative singular form:

• розовый → masculine
• розовая → feminine
• розовое → neuter
• розовые → plural

That is why you get розовая папка.

A few clues help:

1. Папка is in the nominative case, which is the usual case for the subject.
2. The verb лежит is singular, matching папка.
3. На столе is a location phrase, not the subject.

So the basic structure is:

• На столе = location
• лежит = verb
• розовая папка = subject

Even though the subject comes later in the sentence, it is still the subject.

Russian word order is flexible, and it often changes for focus or information structure, not basic grammar.

Starting with На столе puts the location first, as if setting the scene:

• На столе лежит розовая папка. = On the table there is a pink folder.

If you say:

• Розовая папка лежит на столе.

that is also correct, but it feels more like you are talking about the pink folder specifically and then saying where it is.

So both are grammatical; the difference is mostly about emphasis.

Russian has no articles.

So папка can mean:

• a folder
• the folder

The exact meaning depends on context.

In this sentence, English might translate it as either a pink folder or the pink folder, depending on the situation. Russian leaves that unstated unless context makes it clear.

Yes.

Папка is singular, so the verb is singular too:

• лежит = singular
• лежат = plural

For example:

• На столе лежит розовая папка. = A pink folder is lying on the table.
• На столе лежат розовые папки. = Pink folders are lying on the table.

The main stresses are:

• на столе́
• лежи́т
• ро́зовая
• па́пка

Stress matters in Russian, so it is good to learn words together with their stress. In particular, столе́ and лежи́т may not be obvious to an English speaker.

Yes, but it changes the tone.

• На столе лежит розовая папка. = natural, everyday, visually concrete
• На столе находится розовая папка. = more formal, neutral, less vivid

Находится is closer to is located, while лежит tells you the folder's physical position. In ordinary speech, лежит is usually the better choice here.