Το βιβλίο είναι πάνω στην επιφάνεια.

A word-by-word breakdown:

• Το = the
• βιβλίο = book
• είναι = is
• πάνω = on / on top / above depending on context
• στην = a contracted form of σε την, here meaning on the
• επιφάνεια = surface

So the structure is:

• Το βιβλίο = the book
• είναι = is
• πάνω στην επιφάνεια = on the surface

Because βιβλίο is a neuter singular noun in Greek.

Greek nouns have grammatical gender, and the article must agree with the noun.
For βιβλίο, the correct definite article is το.

So:

• το βιβλίο = the book

In this sentence, το βιβλίο is the subject, so it is in the nominative singular. For neuter nouns like this, the nominative singular article is το.

Πάνω literally has the basic idea of up / on top.

In a sentence like this, it helps form the meaning on in the physical sense of being on top of something. Learners can think of:

• πάνω σε / πάνω στο / πάνω στην = on

So:

• πάνω στην επιφάνεια = on the surface

By itself, πάνω can also mean up or above, depending on context, so the rest of the phrase matters.

Because στην is the normal contracted form of σε την in Modern Greek.

This kind of contraction is very common:

• σε + το → στο
• σε + τη(ν) → στη / στην
• σε + τον → στον

So:

• πάνω στην επιφάνεια literally comes from πάνω σε την επιφάνεια

In normal modern usage, you would usually say and write στην, not σε την, here.

It is in the accusative singular.

Why? Because after σε and expressions like πάνω σε, Modern Greek normally uses the accusative.

So the phrase is:

• στην επιφάνεια

where:

• την = feminine singular accusative article
• επιφάνεια = feminine singular noun

This is a very common Greek pattern:
preposition/expression + accusative.

Because grammatical gender in Greek is a property of the noun itself, not necessarily something logical or physical.

The noun επιφάνεια is simply a feminine noun, so it takes feminine forms like:

• η επιφάνεια = the surface (nominative)
• την επιφάνεια = the surface (accusative)

English speakers often want gender to feel meaningful, but in Greek you usually just have to learn the noun together with its article.

A good habit is to learn nouns as units:

• το βιβλίο
• η επιφάνεια

Sometimes Greek can use σε / στην by itself, but πάνω στην is more explicit about the idea of on top of a surface.

Compare the feel:

• πάνω στην επιφάνεια = clearly on the surface / on top of the surface
• στην επιφάνεια = can be more general, and in some contexts can even feel more abstract or less specifically physical

So in this sentence, πάνω στην is a very natural way to say that the book is resting on the surface.

This is an important distinction:

• πάνω στην / πάνω σε / πάνω στο = on, usually with contact
• πάνω από = above / over, not necessarily touching

So:

• Το βιβλίο είναι πάνω στην επιφάνεια = the book is on the surface
• Το βιβλίο είναι πάνω από την επιφάνεια = the book is above the surface

If the book is physically resting on it, πάνω στην is the right choice.

Yes. Επάνω is a fuller form of πάνω.

In many situations, both are possible:

• πάνω στην επιφάνεια
• επάνω στην επιφάνεια

In everyday speech, πάνω is extremely common.
Επάνω can sound a bit fuller or slightly more formal/emphatic, depending on context.

For a learner, πάνω is the most useful everyday form to know first.

No, Greek word order is more flexible than English word order.

The sentence:

• Το βιβλίο είναι πάνω στην επιφάνεια

is a neutral, natural way to say it.

But Greek can move things around for emphasis. For example, a speaker might front the location to emphasize where the book is. Even so, the original order is the safest and most standard one for learners.

So the short answer is:

• not completely fixed
• but the given order is normal and natural

A simple pronunciation guide:

• Το = to
• βιβλίο = vee-VLEE-o
• είναι = EE-ne
• πάνω = PA-no
• στην = stin
• επιφάνεια = eh-pee-FA-nya

A smoother whole-sentence version:

• to vee-VLEE-o EE-ne PA-no stin eh-pee-FA-nya

A few useful notes:

• β is pronounced like v
• ει in είναι sounds like ee
• the stress matters: βιβλίο, είναι, πάνω, επιφάνεια

The accent marks show which syllable is stressed.