Jeden spinacz nie wystarczy do tego raportu, więc wezmę dwa.

Because spinacz is a masculine noun in Polish.

Polish numerals like one have different forms depending on gender:

• jeden — masculine
• jedna — feminine
• jedno — neuter

So:

• jeden spinacz = one paper clip
• jedna książka = one book
• jedno okno = one window

Since spinacz is masculine, jeden is the correct form.

For the same reason: the form of two depends on gender.

• dwa is used with masculine and neuter nouns
• dwie is used with feminine nouns

So:

• dwa spinacze = two paper clips
• dwie książki = two books

Because spinacz is masculine, the sentence uses dwa.

Yes, wezmę dwa spinacze would be completely correct.

But in Polish, just like in English, you can leave out a noun if it is obvious from context. Since spinacz was already mentioned, wezmę dwa naturally means I’ll take two [paper clips].

So both are possible:

• wezmę dwa = I’ll take two
• wezmę dwa spinacze = I’ll take two paper clips

The shorter version sounds natural because the object is already understood.

Raportu is in the genitive singular.

That happens because the preposition do requires the genitive case.

So:

• raport = nominative
• do raportu = to/for the report

In this sentence, do tego raportu means something like for this report.

More examples with do:

• do domu = to home / to the house
• do szkoły = to school
• do biura = to the office

So raportu is not random—it is there because do demands the genitive.

Because ten raport is the nominative form, but after do you need the genitive.

The demonstrative this changes with case too:

• ten raport = this report
• do tego raportu = for this report

So both the noun and the word ten must change:

• ten → tego
• raport → raportu

This is a very common pattern in Polish: adjectives, demonstratives, and nouns usually all change together to match case.

This is a very common Polish feature.

Wystarczy is the present-form shape of a perfective verb: wystarczyć.
Perfective verbs do not normally describe an ongoing present action. Their present-form endings usually refer to the future.

So:

• wystarcza = is enough / is being sufficient / generally suffices
  imperfective
• wystarczy = will be enough
  perfective

That is why jeden spinacz nie wystarczy means one paper clip won’t be enough.

This is one of the key things to learn in Polish verb aspect:

• imperfective often handles present or repeated action
• perfective often gives a completed future meaning

Polish often has an imperfective / perfective pair of verbs.

For to take, the common pair is:

• brać — imperfective
• wziąć — perfective

Wezmę is the 1st person singular future meaning of the perfective verb wziąć:

• wezmę = I will take

This form can feel irregular because it does not look much like wziąć at first. That is just something learners usually need to memorize.

Why use wezmę here instead of a form from brać?
Because the speaker means a single completed action: I’ll take two.

Compare:

• wezmę dwa = I’ll take two
• będę brał dwa / będę brała dwa = I’ll be taking two / I’ll take two repeatedly or in a more ongoing sense

In this sentence, the perfective wezmę is the natural choice.

Więc means so, therefore, or thus.

It connects the two ideas:

• Jeden spinacz nie wystarczy = One paper clip won’t be enough
• więc wezmę dwa = so I’ll take two

It shows result or consequence.

Very similar words in English:

• so
• therefore
• that’s why

In everyday Polish, więc is very common and natural.

Because in Polish, nie is normally written separately from finite verb forms.

So:

• nie wystarczy = will not be enough
• nie mam = I don’t have
• nie wiem = I don’t know

This is the normal spelling rule for verbs.

Learners often notice that in some languages negation attaches to the verb, but in Polish it is usually written as a separate word.

In this sentence, yes, paper clip is the most natural meaning.

Spinacz is a general word connected with something that clips or fastens, but in office context it usually means paper clip. If someone wants to be extra specific, they may say:

• spinacz do papieru
• spinacz biurowy

But in normal everyday speech, just spinacz is often enough when the context is clear.

Yes, you could.

• Jeden spinacz nie wystarczy = One paper clip won’t be enough
• Spinacz nie wystarczy = A paper clip / one paper clip won’t be enough

Adding jeden makes the number one explicit and gives a stronger contrast with dwa later in the sentence.

So the version with jeden ... dwa is especially neat because it highlights the contrast:

• one is not enough
• I’ll take two

Because Polish has no articles.

English distinguishes between:

• a report
• the report

Polish usually does not use separate words for this. The meaning is understood from context.

So raport can mean:

• a report
• the report

And do tego raportu makes it more specific by saying for this report.

This is very normal in Polish, so you should not expect direct equivalents of English a/an/the in every sentence.