Priset på boken är ganska högt.

Because priset is the definite singular form of ett pris (a price).

• ett pris = a price
• priset = the price

In this sentence, we are talking about a specific price, so Swedish uses the definite form priset.

For the same reason: boken is the definite singular form of en bok.

• en bok = a book
• boken = the book

So priset på boken literally means the price on the book, but in natural English it means the price of the book.

Yes, på often means on, but in Swedish it is also used in some expressions where English uses of or for.

So:

• priset på boken = the price of the book
• more literally: the price on the book

This is just the normal Swedish pattern with pris.

You will also see similar expressions like:

• priset på maten = the price of the food
• priset på bensin = the price of petrol/gasoline

Because Swedish often makes both nouns definite in this kind of phrase when both are specific.

• priset på boken = the price of the book

If the book were not specific, you could say:

• priset på en bok = the price of a book

So the definite forms show that we are talking about the price of the book, not just any price or any book.

Because pris is a neuter noun: ett pris.

In Swedish, adjectives agree with the noun they describe. When an adjective is used after är with a singular neuter noun, it usually takes -t.

• en bok är dyr = a book is expensive
• ett pris är högt = a price is high

So:

• hög = common-gender form
• högt = neuter form

Since pris is an ett-word, högt is correct.

It describes priset (the price), not boken (the book).

The structure is:

• Priset på boken = the subject
• är = is
• ganska högt = quite high

So the idea is The price is quite high, not The book is quite high.

Ganska usually means quite, rather, or fairly.

It often gives a moderate meaning, not extremely strong.

So:

• högt = high
• ganska högt = quite high / fairly high

It suggests the price is noticeably high, but not necessarily shockingly high.

Yes, but the meaning changes.

• ganska högt = quite/fairly high
• mycket högt = very high

Mycket is stronger.
So if you want a milder statement, ganska is better.

This is normal Swedish word order. In a main clause, the finite verb usually comes in second position.

Here, the first element is the whole subject phrase:

• Priset på boken = first element
• är = second position

So the structure is completely normal Swedish:

• Priset på boken är ganska högt.

This is an example of the Swedish V2 rule.

Yes. That means The book is quite expensive.

That sentence is often more natural in everyday speech. Compare:

• Priset på boken är ganska högt. = The price of the book is quite high.
• Boken är ganska dyr. = The book is quite expensive.

The meaning is very similar, but the focus is slightly different:

• priset sentence focuses on the price
• dyr sentence focuses on the book as expensive

You learn it as part of the noun:

• ett pris
• priset

There is no reliable universal rule that lets you always guess noun gender, so it is best to memorize nouns together with their article.

For example:

• ett pris
• en bok

That also helps you choose the right adjective form later, like högt with ett pris.

A careful approximate pronunciation is:

PRI-set po BOO-ken air GANS-ka HUGT

A few notes:

• priset: the stress is on the first syllable
• på has a long å sound
• boken also has stress on the first syllable
• är is often pronounced very lightly in normal speech
• högt has a vowel sound that does not exist in English, so it may take practice

The rhythm is quite smooth:

Priset på boken är ganska högt.

If you want to say A book’s price is quite high or The price of a book is quite high, you can make book indefinite:

• Priset på en bok är ganska högt.

You could also make price indefinite in some contexts:

• Ett pris på en bok är ganska högt.

But that is less natural in many situations. Usually, when talking about the cost of something, Swedish often uses the definite priset.