Ta młoda zawodniczka biega szybciej niż ten zawodnik z tamtej drużyny.

These are all forms of Polish demonstratives, like this or that in English.

• ta = this for a feminine noun
• ten = this for a masculine noun
• tamtej = that for a feminine noun, here in a different case

They match the nouns they describe:

• ta młoda zawodniczka → this young female athlete
• ten zawodnik → this male athlete
• z tamtej drużyny → from that team

So the form changes because Polish demonstratives must agree with the noun in gender, number, and case.

They both mean athlete or competitor, but:

• zawodniczka = female athlete
• zawodnik = male athlete

This is a very common pattern in Polish:

• masculine form: -nik
• feminine counterpart: often -niczka

So the sentence contrasts a woman and a man:

• Ta młoda zawodniczka = This young female athlete
• ten zawodnik = this male athlete

Because młoda has to agree with zawodniczka, which is a feminine singular noun.

Polish adjectives change form to match the noun:

• młody zawodnik = young male athlete
• młoda zawodniczka = young female athlete
• młode dziecko = young child

So młoda is simply the feminine singular form of młody.

Szybciej means faster. It is the comparative form of the adverb szybko (quickly / fast).

Forms:

• szybko = fast
• szybciej = faster
• najszybciej = fastest

In this sentence, biega szybciej means runs faster.

A useful distinction:

• szybki = fast, quick (adjective)
• szybko = quickly, fast (adverb)
• szybciej = faster (comparative adverb)

Since it describes how she runs, Polish uses the adverb form.

Niż means than in comparisons.

So:

• biega szybciej niż ten zawodnik = runs faster than this athlete

It is the normal word used after a comparative like:

• większy niż = bigger than
• lepszy niż = better than
• wolniej niż = more slowly than

You may also see od in some comparisons, but niż is very common and very natural here.

Because the preposition z here means from, and z requires the genitive case.

Base form:

• ta drużyna = this team
• tamta drużyna = that team

After z:

• z tej drużyny = from this team
• z tamtej drużyny = from that team

So both words change:

• tamta → tamtej
• drużyna → drużyny

This is a very common thing in Polish: prepositions often force a particular case.

Not quite.

• tej = this / that depending on context
• tamtej = more clearly that one over there / that

So:

• z tej drużyny = from this team
• z tamtej drużyny = from that team

The contrast is similar to:

• this team
• that team

In everyday English, that is enough, but Polish keeps a clearer distinction through words like ta / tamta.

This is a very useful distinction.

• biegać → biega = to run regularly / habitually / in general
• biec → biegnie = to be running right now, or to run in a single instance

So:

• Ta zawodniczka biega szybko. = This athlete runs fast / is a fast runner.
• Ta zawodniczka biegnie szybko. = This athlete is running fast right now.

In your sentence, biega szybciej niż... sounds like a general comparison of ability or usual performance, not just one moment.

Yes. Polish word order is more flexible than English because endings show the grammatical relationships.

The basic sentence:

• Ta młoda zawodniczka biega szybciej niż ten zawodnik z tamtej drużyny.

Other possible orders can shift emphasis, for example:

• Szybciej biega ta młoda zawodniczka niż ten zawodnik z tamtej drużyny.
• Ta młoda zawodniczka szybciej biega niż ten zawodnik z tamtej drużyny.

These all point to roughly the same meaning, but the original version is the most neutral and natural for a learner.

Yes. Using ta and ten makes them sound specific:

• ta młoda zawodniczka = this young female athlete
• ten zawodnik = this athlete / this male athlete

It suggests the speaker has particular people in mind, not athletes in general.

Compare:

• Młoda zawodniczka biega szybciej niż zawodnik z tamtej drużyny.
  = A young female athlete runs faster than an athlete from that team.
  This is less specific.

So the demonstratives make the sentence more definite and concrete.

A rough pronunciation guide:

• zawodniczka ≈ za-vod-NEECH-ka
• szybciej ≈ SHIB-chay
• niż ≈ neesh

A couple of helpful sound notes:

• sz sounds like sh
• cz sounds like ch
• ż sounds like the s in measure
• ciej in szybciej is a compact sound, roughly like chay

So szybciej niż sounds roughly like SHIB-chay neesh.

Yes. Zawodnik / zawodniczka can mean:

• athlete
• competitor
• contestant
• player

The exact translation depends on context.

For example:

• in sports: athlete, player
• in a race or competition: competitor, contestant

So in this sentence, athlete is a good natural translation, but competitor could also work depending on the broader context.