Na spotkanie przyszły dwadzieścia trzy osoby, więc musiałam przestawić kilka krzeseł.

Here na spotkanie means to the meeting.

Polish often uses na + accusative with events when you mean movement to them:

• iść na spotkanie = to go to a meeting
• przyjść na koncert = to come to a concert
• jechać na imprezę = to go to a party

So na spotkanie przyszły... literally means ...came to the meeting.

Because przyszli is used for masculine-personal plural subjects, while przyszły is used for other plural subjects.

Even though osoby means people, grammatically it is a feminine plural noun, not a masculine-personal one. So it takes przyszły:

• kobiety przyszły = the women came
• osoby przyszły = the people/persons came
• studenci przyszli = the male/mixed students came

So in this sentence, przyszły agrees correctly with osoby.

With numbers ending in 2, 3, 4 (except 12, 13, 14), non-masculine-personal nouns usually appear in the nominative plural:

• dwadzieścia dwie osoby
• dwadzieścia trzy osoby
• dwadzieścia cztery osoby

That is why you get osoby, not osób.

A useful contrast:

• dwadzieścia trzy osoby = 23 people
• dwadzieścia pięć osób = 25 people

So the ending of the number affects the form of the noun.

Because dwadzieścia trzy and kilka behave differently.

• dwadzieścia trzy osoby uses the pattern for numbers ending in 3, so the noun is nominative plural
• kilka requires the noun to be in the genitive plural

So:

• osoby = nominative plural
• krzeseł = genitive plural of krzesło

Compare:

• trzy krzesła = three chairs
• kilka krzeseł = several chairs

Musiałam tells you the speaker is female.

In Polish past tense, the 1st person singular shows gender:

• musiałam = I had to (female speaker)
• musiałem = I had to (male speaker)

So this sentence was said by a woman.

Because Polish often drops subject pronouns when they are already clear from the verb form.

Musiałam already means:

• I had to
• and it also shows the speaker is female

So ja is unnecessary unless you want emphasis:

• Musiałam przestawić kilka krzeseł. = neutral
• Ja musiałam przestawić kilka krzeseł. = I had to move several chairs

After musieć (to have to / must), Polish normally uses an infinitive:

• muszę iść = I must go
• musiałam przestawić = I had to move/rearrange

So musiałam przestawić is the normal structure.

Also, przestawić is perfective, which suggests a completed action: the chairs had to be rearranged as a finished task.

This is about aspect.

• przestawić = perfective, a completed action
• przestawiać = imperfective, ongoing or repeated action

In this sentence, the speaker means she had to rearrange some chairs as a practical result of 23 people arriving. That sounds like a single completed action, so przestawić fits well.

If you said musiałam przestawiać kilka krzeseł, it would sound more like the action was in progress, repeated, or viewed without focus on completion.

Kilka means a few or several.

It is not an exact number. It usually suggests a small number, but the speaker is not being precise.

So kilka krzeseł means something like:

• a few chairs
• several chairs

Yes. Polish word order is fairly flexible.

This sentence starts with Na spotkanie, which sets the scene first:

• Na spotkanie przyszły dwadzieścia trzy osoby...

You could also say:

• Dwadzieścia trzy osoby przyszły na spotkanie...

Both are natural, but the focus shifts a bit:

• Na spotkanie... emphasizes the event/context first
• Dwadzieścia trzy osoby... emphasizes the number of people first

Because przyszły focuses on arrival: the people came to the meeting.

If you said:

• Na spotkaniu były dwadzieścia trzy osoby

that would mean There were 23 people at the meeting, focusing on presence rather than arrival.

So:

• przyszły = came / turned up
• były = were present

Więc means so, therefore, or as a result.

It connects the two parts logically:

• Na spotkanie przyszły dwadzieścia trzy osoby
• więc musiałam przestawić kilka krzeseł

In other words: 23 people came, so I had to rearrange some chairs.

It is a very common, natural connector in everyday Polish.

Because Polish does not have articles like English a/an and the.

So nouns like spotkanie, osoby, and krzeseł appear without articles, and the exact meaning comes from context.

Depending on context:

• spotkanie can mean a meeting or the meeting
• osoby can mean people or the people
• krzesła / krzeseł can mean chairs or the chairs

That is completely normal in Polish.