Ten fotel jest niewygodny, więc wolę kanapę.

Because fotel is a masculine noun in Polish, and the demonstrative this has to agree with the noun’s gender.

• ten = masculine
• ta = feminine
• to = neuter

So:

• ten fotel = this armchair
• ta kanapa = this sofa
• to krzesło = this chair (if the noun were neuter)

Agreement is a very important feature of Polish grammar.

Fotel usually means an armchair or an upholstered chair, not just any chair.

So in this sentence:

• fotel = armchair
• kanapa = sofa / couch

That is why the sentence contrasts two different pieces of furniture: this armchair is uncomfortable, so I prefer the sofa.

Niewygodny means uncomfortable.

It is built from:

• wygodny = comfortable
• nie- = not / un-

So:

• wygodny = comfortable
• niewygodny = uncomfortable

The ending -y is there because the adjective must agree with fotel, which is masculine singular.

Compare:

• ten fotel jest niewygodny = this armchair is uncomfortable
• ta kanapa jest niewygodna = this sofa is uncomfortable
• to łóżko jest niewygodne = this bed is uncomfortable

Often, yes. It is a very useful comparison.

Examples:

• wygodny → niewygodny = comfortable → uncomfortable
• miły → niemiły = nice → unpleasant / not nice
• możliwy → niemożliwy = possible → impossible

But do not assume it works exactly like English in every single case. The basic idea is right, though: nie- often creates the negative form of an adjective.

In the present tense, Polish normally does use jest in sentences like this.

• Ten fotel jest niewygodny. = This armchair is uncomfortable.

You may sometimes see jest omitted in very informal, stylistic, or headline-like language, but for learners the normal pattern is:

noun + jest + adjective

So Ten fotel niewygodny would sound incomplete or unnatural in ordinary standard speech.

Więc means so, therefore, or thus.

It introduces a result:

• Ten fotel jest niewygodny, więc wolę kanapę.
• This armchair is uncomfortable, so I prefer the sofa.

It is a very common linking word in Polish.

Other possible connectors with similar meanings include:

• dlatego = therefore / that’s why
• więc = so / therefore

In everyday conversation, więc is very common and natural.

Because więc connects two clauses, and in Polish it is standard to put a comma before it.

So:

• Ten fotel jest niewygodny, więc wolę kanapę.

This punctuation is normal and expected in Polish writing.

Wolę is the 1st person singular present tense of the verb woleć, which means to prefer.

So:

• woleć = to prefer
• wolę = I prefer

Other forms include:

• wolisz = you prefer
• woli = he/she/it prefers
• wolimy = we prefer
• wolicie = you (plural) prefer
• wolą = they prefer

In this sentence, the subject I is understood from the verb form, so Polish does not need ja.

Because kanapa is the direct object of wolę, so it takes the accusative case.

The dictionary form is:

• kanapa = sofa / couch

But after wolę = I prefer, you need the accusative:

• wolę kanapę = I prefer the sofa

This happens because many Polish verbs require their object in the accusative case.

Compare:

• Mam kanapę. = I have a sofa.
• Widzę kanapę. = I see the sofa.
• Wolę kanapę. = I prefer the sofa.

Yes.

Kanapa is a feminine noun, and for many feminine nouns ending in -a, the accusative singular changes to -ę.

So:

• nominative: kanapa
• accusative: kanapę

This is a very common pattern:

• książka → książkę
• herbata → herbatę
• lampa → lampę

So wolę kanapę follows a very regular rule.

Because Polish often leaves out subject pronouns when the verb already makes the subject clear.

• wolę already means I prefer
• so ja wolę is usually unnecessary

Both are possible, but they are used differently:

• wolę kanapę = neutral, normal
• ja wolę kanapę = I prefer the sofa, with emphasis or contrast

For example:

• Ty wolisz fotel, a ja wolę kanapę.
• You prefer the armchair, and I prefer the sofa.

Yes, Polish word order is more flexible than English word order, although not every version sounds equally natural in every context.

The most neutral version here is:

• Ten fotel jest niewygodny, więc wolę kanapę.

But you could also say, for emphasis:

• Wolę kanapę, bo ten fotel jest niewygodny.
  = I prefer the sofa because this armchair is uncomfortable.

You can move elements around to change focus, contrast, or style, but the original sentence is a very natural standard order.

A simple learner-friendly guide:

• ten ≈ ten (but with Polish e)
• fotel ≈ FO-tehl
• jest ≈ yest
• niewygodny ≈ nye-vy-GOD-ny
• więc ≈ roughly vyents or vyentsh-like, depending on the speaker
• wolę ≈ VO-le(n) with a nasal ending
• kanapę ≈ ka-NA-pe(n) with a nasal ending

A few key points:

1. Polish stress is usually on the second-to-last syllable:

   • FO-tel
   • nie-wy-GOD-ny
   • wo-LĘ
   • ka-NA-pę

2. ę is a nasal vowel, but in real speech its pronunciation changes depending on what follows.
   At the end of a word, learners can think of it approximately as a nasalized e.

3. wi in więc sounds more like vyen than English ween.

You do not need perfect nasal vowels right away; being understood matters more at first.

They are similar, but not exactly identical in feel.

• więc = so / therefore
• dlatego = that’s why / therefore

Compare:

• Ten fotel jest niewygodny, więc wolę kanapę.
• Ten fotel jest niewygodny, dlatego wolę kanapę.

Both are correct.
Więc is often a little more conversational and direct.
Dlatego can sound slightly more explicit: for that reason.

Not if you want the same meaning.

• wolę kanapę = I prefer the sofa
• lubię kanapę = I like the sofa

Woleć expresses a comparison or choice.
The sentence implies choosing the sofa over the armchair because the armchair is uncomfortable.

So wolę is the right verb here.