Na kolację zrobię makaron ze szpinakiem i twarogiem, bo robi się go szybko.

Because na here means for, as in for dinner.

In this expression, na takes the accusative case, so:

• kolacja = dinner
• na kolację = for dinner

This is a very common pattern in Polish:

• na śniadanie = for breakfast
• na obiad = for lunch/dinner
• na kolację = for dinner/supper

So kolację is simply the accusative singular form of kolacja.

Zrobię is the 1st person singular future of the perfective verb zrobić.

That matters because Polish often uses:

• perfective verbs for a single completed action
• imperfective verbs for an ongoing, repeated, or unfinished action

So:

• zrobię makaron = I’ll make the pasta / I’ll prepare the pasta
  (one complete action)
• robię makaron = I’m making pasta / I make pasta
• będę robić makaron = I’ll be making pasta
  (focus on the process, less on completion)

In this sentence, the speaker is talking about a plan for one meal, so zrobię is the most natural choice.

Usually no. In Polish, makaron is a general word for pasta.

Depending on context, it can mean:

• pasta in general
• noodles
• a pasta dish

So in this sentence, makaron is best understood as pasta rather than specifically macaroni.

Because makaron is the direct object, so it is in the accusative case — but for many masculine inanimate nouns, the accusative singular looks exactly the same as the nominative singular.

So:

• makaron = nominative
• makaron = accusative

That is why the form does not visibly change.

Ze is just a pronunciation variant of z.

Polish uses ze instead of z before some sounds or clusters when z would be awkward to pronounce. Since szpinakiem begins with szp-, ze szpinakiem sounds much more natural than z szpinakiem.

So:

• z = with / from
• ze = the same word, just a smoother pronunciation in certain contexts

Because z / ze meaning with requires the instrumental case.

So:

• szpinak → ze szpinakiem
• twaróg → z twarogiem

That is why both ingredients appear in the instrumental.

A useful thing to remember is that many masculine singular nouns in the instrumental end in -em.

Also, in twarogiem, the ó changes to o, which is a normal spelling alternation in Polish inflection:

• twaróg
• twarogu
• twarogiem

Bo means because.

It is very common in everyday Polish and sounds natural in speech.

Yes, you could also use ponieważ, but the tone changes a little:

• bo = everyday, conversational
• ponieważ = more formal, more written-style

So this sentence with bo sounds natural and ordinary.

Here robi się is not really reflexive in the sense of does itself.

Instead, Polish often uses się to make an impersonal or general statement, similar to:

• one makes
• people make
• you make
• it is made

So robi się go szybko means something like:

• you make it quickly
• it can be made quickly
• it’s quick to make

This is a very common Polish structure.

Go refers back to makaron.

It is the short accusative form meaning him/it, and here it means it:

• makaron = pasta
• go = it

So robi się go szybko literally means one makes it quickly.

Without go, the sentence would feel incomplete in this structure, because robić normally needs an object here.

Because go is the normal short, unstressed form.

In Polish, both go and jego can mean him/it in some contexts, but:

• go = the usual short form
• jego = fuller, more emphatic form, or used after a preposition

Here there is no emphasis, so go is the natural choice:

• robi się go szybko = natural
• robi się jego szybko = unnatural in this sentence

Yes. Polish word order is more flexible than English word order.

This sentence is natural as written:

• bo robi się go szybko

But you could also say:

• bo szybko się go robi

That version puts a little more focus on quickly.

Not every possible order sounds equally natural, though, because little words like się and go have preferred positions. So while Polish is flexible, it is not random.

Because in Polish, a clause introduced by bo is normally separated by a comma.

So:

• Na kolację zrobię makaron ze szpinakiem i twarogiem, bo robi się go szybko.

This is standard Polish punctuation.