Ten pierścionek jest droższy niż tamten.

They are demonstratives: words like this and that.

• ten = this
• tamten = that

Both are in the masculine singular nominative form because they refer to pierścionek, which is a masculine singular noun.

So:

• ten pierścionek = this ring
• tamten = that one / that ring

In the second part, pierścionek is omitted because it is already understood.

In Polish, every noun has a grammatical gender. Pierścionek is a masculine noun.

You can see that the other words in the sentence agree with it:

• ten → masculine singular
• droższy → masculine singular

This agreement is very important in Polish. If the noun were feminine or neuter, those forms would change.

For example:

• masculine: ten pierścionek jest droższy
• feminine: ta książka jest droższa
• neuter: to auto jest droższe

The basic form is drogi, which means expensive.

Droższy is the comparative form, meaning more expensive.

So:

• drogi = expensive
• droższy = more expensive

This is similar to English cheap → cheaper or expensive → more expensive, except in Polish the form often changes directly rather than always using a separate word like more.

It is formed with a stem change, so it is not completely predictable from English.

• basic adjective: drogi
• comparative: droższy

Notice the changes:

• g changes to ż
• the ending changes as well

This kind of consonant change is common in Polish adjective comparisons.

You do not usually say bardziej drogi in normal usage here. Polish strongly prefers droższy.

Niż means than in comparisons.

So in this sentence:

• droższy niż tamten = more expensive than that one

It is the normal word used after a comparative adjective like:

• lepszy niż = better than
• gorszy niż = worse than
• tańszy niż = cheaper than

Yes. In many cases, Polish allows both patterns:

• Ten pierścionek jest droższy niż tamten.
• Ten pierścionek jest droższy od tamtego.

Both mean the same thing.

The difference is grammatical:

• after niż, you often keep the comparison in a form matching the original noun phrase
• after od, you use the genitive

That is why you get:

• niż tamten
• od tamtego

Both are natural.

Because niż does not force the genitive in this kind of sentence.

Here, tamten stands for tamten pierścionek, and it stays in the same basic form as the understood noun phrase.

But if you use od, then you need the genitive:

• niż tamten
• od tamtego

So tamten is correct with niż, and tamtego is correct with od.

In a normal sentence like this, yes, you should include jest.

Polish usually does use the present-tense form of to be in sentences like:

• On jest wysoki.
• Ten pierścionek jest droższy.

So unlike some other Slavic languages, standard Polish does not normally drop the present-tense copula in everyday sentences.

Because Polish, like English, often omits repeated words when they are obvious from context.

So instead of saying:

• Ten pierścionek jest droższy niż tamten pierścionek

Polish normally says:

• Ten pierścionek jest droższy niż tamten

This sounds more natural and avoids repetition.

It is in the nominative case because it is the subject of the sentence.

The sentence structure is:

• Ten pierścionek = subject
• jest droższy = predicate
• niż tamten = comparison

So pierścionek stays in the nominative.

The given word order is the most neutral and natural one:

• Ten pierścionek jest droższy niż tamten.

Polish word order is fairly flexible, but changing it usually adds emphasis or sounds more marked.

For example, you might also hear:

• Droższy jest ten pierścionek niż tamten.

But that is less neutral and more context-dependent. For learners, the original order is the safest choice.

A rough English-friendly guide:

• pierścionek ≈ PYER-shcho-nek
• droższy ≈ DROZH-shy

A few useful sound notes:

• ś is a soft sh sound
• cz / sz are different Polish sounds, but in droższy the cluster is hard for learners and may sound roughly like zh-sh
• ż sounds like the s in measure
• rz often sounds like ż

You do not need perfect pronunciation immediately; the main challenge is the consonant clusters.

Both can refer to a ring, but they are not always used in exactly the same way.

• pierścionek usually means a ring worn as jewelry, especially a decorative ring
• pierścień is broader and can mean a ring-shaped object, a band, a circle, or sometimes a ring in a more formal or specific sense

In this sentence, pierścionek is the natural everyday word for a jewelry ring.