Nie lubię się kłócić o małe rzeczy.

Not exactly. In kłócić się, się is part of the verb, and it does not usually mean oneself in a literal English sense.

• kłócić się = to argue / to quarrel
• So Nie lubię się kłócić means I don’t like to argue

Many Polish verbs are used with się even when English does not use myself/yourself/etc. This is one of them.

Because kłócić się is the normal verb meaning to argue.

Without się, kłócić usually has a different meaning, more like:

• to make people conflict
• to clash
• to contradict / be inconsistent with

For example:

• To się kłóci z logiką. = That contradicts logic.

So if you want to say to argue with someone / about something, you normally need kłócić się.

Because after lubić (to like), Polish often uses an infinitive to say like doing something.

So:

• lubię czytać = I like reading / I like to read
• lubię gotować = I like cooking
• nie lubię się kłócić = I don’t like arguing

This works very much like English like + -ing or like + to + verb.

This is a question of aspect.

• kłócić się = imperfective
• pokłócić się = perfective

After lubić / nie lubić, Polish normally uses the imperfective when talking about an activity in general.

So:

• Nie lubię się kłócić. = I don’t like arguing in general

Using pokłócić się would sound more like to have an argument / end up arguing once, which does not fit as naturally after nie lubię in this sentence.

Here o means about / over.

With kłócić się o..., Polish expresses what the argument is about:

• kłócić się o pieniądze = to argue about money
• kłócić się o politykę = to argue about politics
• kłócić się o małe rzeczy = to argue over little things

So this is a very useful pattern:

kłócić się o + accusative

It is accusative plural, because o in this meaning takes the accusative.

The full phrase is:

• o małe rzeczy

Here:

• małe = accusative plural of mały (small)
• rzeczy = accusative plural of rzecz (thing)

A detail that often confuses learners: in this phrase, rzeczy looks the same as the nominative plural form. That is normal. In Polish, some case forms are identical in appearance.

The plural sounds natural because the sentence is talking about small things in general, not one specific small thing.

• o małe rzeczy = over little things / over small matters

If you used singular:

• o małą rzecz

that would mean about one small thing, which changes the meaning.

So the plural here matches the general idea: the speaker does not like arguing over petty matters.

Yes. That word order is also correct.

Both are possible:

• Nie lubię się kłócić o małe rzeczy.
• Nie lubię kłócić się o małe rzeczy.

In modern Polish, się is fairly flexible in position, though it cannot usually stand at the very beginning of a clause.

In this sentence, both versions sound natural. The version with się before the infinitive is very common.

Because in Polish, nie is normally written separately from verbs.

So:

• lubię = I like
• nie lubię = I don’t like

This is a basic spelling rule:

• nie
  • verb = separate words

For example:

• nie wiem = I don’t know
• nie chcę = I don’t want
• nie lubię = I don’t like

Małe rzeczy is correct and understandable, but a more idiomatic Polish phrase is often:

• o drobiazgi = over trifles / over little things

So a very natural alternative would be:

• Nie lubię się kłócić o drobiazgi.

The original sentence is still good Polish. Małe rzeczy is simply a bit more literal.

A rough English-style guide is:

Nyeh LOO-byeh shyeh KWOO-cheech oh MAH-weh ZHE-chi

A few important sounds:

• nie sounds roughly like nyeh
• ę in lubię is often pronounced close to -eh in normal speech here
• się sounds roughly like shyeh
• kłócić:
  • kł is like kw
  • ó sounds like oo
  • ć is a soft ch sound
• rz in rzeczy sounds like the s in measure or zh

So:

• kłócić się ≈ KWOO-cheech shyeh
• rzeczy ≈ ZHE-chi

It expresses a general preference, not just what is happening now.

• Nie lubię... = I don’t like...
• It means in general, as part of the speaker’s attitude or personality

So the sentence means something like:

• I’m not the kind of person who likes arguing over small things

If you wanted to talk about a specific moment, Polish would usually build the sentence differently.