Obstawiam odpowiedź numer dwa.

Here obstawiam means something like I’m betting on, I’m going with, or my guess is.

It comes from obstawiać, which literally relates to betting, but in everyday speech it is often used more loosely:

• Obstawiam, że... = I bet that... / I’d say that...
• Obstawiam odpowiedź numer dwa. = I’m going with answer number two.

So it does not have to involve actual money.

Because Polish often leaves out subject pronouns when they are clear from the verb form.

Obstawiam ends in -am, which already tells you it means I:

• obstawiam = I bet / I’m guessing

So ja is unnecessary unless you want emphasis:

• Ja obstawiam odpowiedź numer dwa, a ty numer trzy.
  = I’m going with answer number two, and you’re going with number three.

It is in the accusative singular, because it is the direct object of obstawiam.

However, the form looks exactly the same as the dictionary form:

• nominative: odpowiedź
• accusative: odpowiedź

That is normal for some feminine nouns in Polish, especially ones ending in a soft consonant like -dź, -ść, -ń, and so on.

Because numer dwa means number two as a label.

So:

• odpowiedź numer dwa = answer number two / the answer labeled 2
• druga odpowiedź = the second answer

These can refer to the same thing in some situations, but they are not exactly identical.

If you are choosing from listed options in a quiz, odpowiedź numer dwa is very natural because it points directly to the numbered option.

Because Polish has no articles.

English needs words like a and the, but Polish does not. Context tells you whether something is definite or indefinite.

So odpowiedź numer dwa could be understood as:

• answer number two
• the number two answer
• the answer labeled number two

The exact English wording depends on context.

Yes.

In writing, nr 2 is very common:

• Obstawiam odpowiedź nr 2.

In speech, people normally say:

• numer dwa

So:

• nr 2 = more written/abbreviated
• numer dwa = what you usually say aloud

It is a bit conversational.

It sounds natural in everyday speech, especially when guessing, choosing, or informally expressing a prediction.

If you want something more neutral or formal, you could say:

• Wybieram odpowiedź numer dwa. = I choose answer number two.
• Moja odpowiedź to numer dwa. = My answer is number two.

So obstawiam has a slight flavor of I’m placing my bet on... or my pick is...

Yes, it is present tense.

Polish uses the present tense here for your current choice or guess:

• Obstawiam... = I’m guessing / I’m going with...

In English, we often translate it less literally to sound natural:

• I bet it’s answer number two
• My guess is answer number two
• I’m going with answer number two

So the Polish tense is present, even if the best English translation varies.

Yes, if the context is clear.

If everyone already knows you are talking about answer choices, then:

• Obstawiam numer dwa.

sounds completely natural.

The full version:

• Obstawiam odpowiedź numer dwa.

is just more explicit.

Yes. Polish word order is flexible.

The most neutral version is:

• Obstawiam odpowiedź numer dwa.

But other orders are possible for emphasis:

• Odpowiedź numer dwa obstawiam.
• Numer dwa obstawiam.

These are not wrong, but they sound more marked or contrastive. A learner should usually stick with:

• Obstawiam odpowiedź numer dwa.

A simple learner-friendly approximation would be:

ob-STAH-vyam od-PO-vyedzh NOO-mer dva

A few useful pronunciation notes:

• w sounds like English v
• dwa sounds like dva
• the stress is normally on the second-to-last syllable in each word:
  • obstawiam
  • odpowiedź
  • numer
  • dwa