du timeun ttokgateun jawonbongsa jokkireul ipseupnida.

Because 두 is the form of 둘 used directly before a counter or countable noun.

• 둘 = two
• 두 팀 = two teams

This is a common pattern with native Korean numbers:

• 하나 → 한
• 둘 → 두
• 셋 → 세
• 넷 → 네

So 두 팀 is the natural way to say two teams.

-은/는 is the topic marker.

So 두 팀은 means something like:

• as for the two teams
• the two teams, ...

It marks 두 팀 as the topic of the sentence. In some contexts, -은/는 can also give a slight contrastive feeling, like the two teams (as opposed to others), but often it is just the normal topic marker.

Because Korean often does not need an extra plural marker when the number is already clear.

Here, 두 already tells you there are two teams, so 팀 is enough.

• 두 팀 = two teams
• 두 팀들 = usually unnecessary / less natural in most neutral contexts

Korean uses plural marking much less often than English.

똑같은 is the adnominal form of 똑같다, which means to be exactly the same.

Since it comes before a noun, it has to take this modifying form:

• 똑같다 = to be identical / the same
• 똑같은 조끼 = identical vest / the same vest

This is similar to how English uses an adjective before a noun.

Compare:

• 조끼가 똑같습니다 = The vest is the same.
• 똑같은 조끼 = the same/identical vest

In Korean, modifiers normally come before the noun they describe.

Here:

• 똑같은 modifies 자원봉사 조끼
• 자원봉사 also modifies 조끼

So the structure is:

• 똑같은
  • 자원봉사 조끼
• identical
  • volunteer vest

Korean stacks modifiers before the noun, and this order sounds natural.

It is written as two words here, but it functions like a noun-noun combination:

• 자원봉사 = volunteer work / volunteering
• 조끼 = vest

So 자원봉사 조끼 means a volunteer vest or a vest for volunteering.

This kind of noun + noun combination is very common in Korean.

Because 조끼 is the object of the verb 입다.

• 조끼를 입습니다
• wears a vest

The particle -을/를 marks the direct object.

Here:

• 조끼 ends in a vowel
• so it takes -를

If a noun ends in a consonant, it usually takes -을 instead.

입다 can mean both to put on and to wear, depending on context.

In a sentence like this, it usually means to wear, especially if the sentence is describing what the teams are wearing in general.

So here, 입습니다 is best understood as:

• wear
• are wearing
• sometimes put on, if the context is about the action of dressing

Context decides which English translation sounds best.

Because Korean verbs do not agree with the subject in number or person the way English verbs sometimes do.

So the same verb form can be used with:

• 한 팀은 ... 입습니다 = one team wears ...
• 두 팀은 ... 입습니다 = two teams wear ...

The verb stays the same. Korean does not add a special plural verb ending here.

입습니다 is the formal polite style.

It is commonly used in:

• announcements
• reports
• presentations
• formal writing
• respectful neutral statements

Less formal versions would be:

• 입어요 = polite casual
• 입어 = casual/informal

So this sentence sounds neat, standard, and somewhat formal.

No. It normally means they are wearing the same kind of vest, or identical-looking vests.

So the sentence usually means:

• both teams wear matching volunteer vests
• the vests are the same in design, color, type, etc.

It does not usually mean they are sharing one single vest.

It is commonly pronounced close to 입씀니다.

So the whole sentence may sound roughly like:

• 두 티믄 똑까튼 자원봉사 조끼를 입씀니다

A few things are happening in natural pronunciation:

• 팀은 often sounds like 티믄
• 똑같은 sounds close to 똑까튼
• 입습니다 sounds close to 입씀니다

You do not need to respell it when writing, but it helps to know this when listening.