Takie rzeczy zdarzają się rzadko.

Takie is a form of taki, which means such, that kind of, or like that.

It is takie because it has to agree with rzeczy. The noun rzeczy is:

• feminine
• plural
• nominative here, because it is the subject

So the matching form is takie.

In this sentence, takie rzeczy most naturally means such things or things like that.

Rzeczy is the nominative plural form of rzecz, meaning thing.

Here it is the subject of the sentence, so nominative is needed:

• singular: rzecz
• plural: rzeczy

So takie rzeczy means such things.

A learner may notice that rzeczy can also be other cases in other contexts, but here it is nominative plural because those things are what happen.

Because the subject is plural: takie rzeczy.

Polish verbs agree with the subject in number:

• rzecz zdarza się = a thing happens
• rzeczy zdarzają się = things happen

So zdarzają is the 3rd person plural form.

In this sentence, się is part of the verb zdarzać się, which means to happen or to occur.

So it is best to learn:

• zdarzać się = to happen
• zdarzyć się = to happen once / to occur

Here się does not literally mean themselves. It is not reflexive in the everyday English sense. It is just part of how this verb is normally used.

It is present tense, but it expresses a general truth or a habitual pattern, not only something happening right now.

So zdarzają się rzadko means:

• they happen rarely
• they do not happen often
• this is uncommon

This is very normal in Polish. Just like in English, present tense is often used for general statements:

• Ptaki latają = birds fly
• Takie rzeczy zdarzają się rzadko = such things happen rarely

The infinitive behind zdarzają się is zdarzać się, which is imperfective.

That makes sense because the sentence is about repeated or general occurrence:

• zdarzać się = to happen from time to time / to be something that happens
• zdarzyć się = to happen as a single completed event

Because the sentence means something like this kind of thing does not happen often, the imperfective is the natural choice.

Polish often uses the plural things in general statements like this. Takie rzeczy is very natural and idiomatic.

English often prefers singular expressions such as:

• that kind of thing
• something like that

Polish can use singular too, but it sounds different:

• Taka rzecz zdarza się rzadko is possible, but less natural in everyday speech for this broad meaning
• To się rzadko zdarza is another very common way to say something similar

So the plural in Polish is not strange; it is simply the normal way to speak about this kind of situation.

Yes, the word order can change. Polish word order is flexible.

Takie rzeczy zdarzają się rzadko is a neutral, natural order. Putting rzadko at the end sounds very normal because the sentence ends with the key idea of frequency.

You can also say:

• Takie rzeczy rzadko się zdarzają

That is also correct and natural. The difference is mostly in emphasis and rhythm, not basic meaning.

This is an important distinction.

• takie rzeczy = such things, things like that, that sort of thing
• te rzeczy = these things or those specific things

So in your sentence, takie rzeczy is more general. It refers to a type of event or situation, not a specific set of things already identified.

A rough English-style approximation is:

TA-kye ZHE-chy zda-ZHA-yon shye ZHAT-ko

A few notes:

• rz often sounds like the s in measure
• cz sounds like ch, but harder and retroflex
• się is often pronounced close to shye
• the final vowel in zdarzają is nasal in careful speech

Very roughly, word by word:

• takie ≈ TA-kye
• rzeczy ≈ ZHE-chy
• zdarzają ≈ zda-ZHA-yon
• się ≈ shye
• rzadko ≈ ZHAT-ko

As always, the English approximation is only approximate, but it can help at the beginning.