Na wakacje chciałabym pojechać do Hiszpanii.

In Polish, wakacje is normally a plural-only noun (called pluralia tantum). So Polish talks about the holidays/vacation using a plural form.

That is why you say:

• wakacje są długie = the vacation/holidays are long

Even if English uses singular vacation, Polish usually uses plural wakacje. Also, wakacje often suggests the summer holiday period. For an adult’s time off work, urlop is also very common.

Here na wakacje means something like for vacation, on vacation, or for the holidays.

Polish often uses na + accusative with movement when you are going somewhere for a purpose, occasion, or period:

• jechać na wakacje = go on vacation
• jechać na weekend = go away for the weekend

By contrast, w wakacje usually means during the vacation period and focuses more on time than on the idea of going away for a holiday.

So:

• Na wakacje chciałabym pojechać do Hiszpanii = I’d like to go to Spain for vacation / on vacation
• W wakacje chciałabym pojechać do Hiszpanii would sound more like During the summer holidays, I’d like to go to Spain

It is accusative plural because na here is used with movement.

The useful rule is:

• na + accusative for motion/destination/purpose
• na + locative for location

In this sentence, the form wakacje looks the same as nominative plural, which is normal for this noun. So the case is accusative, even though the spelling does not change.

Chciałabym means I would like or I would want.

It is the 1st person singular feminine conditional form of chcieć (to want).

So:

• chciałabym = said by a woman
• chciałbym = said by a man

This form is softer and less direct than chcę (I want). That is why it is very common when talking about wishes, plans, or polite statements.

In Polish, past-tense and conditional forms often show the speaker’s gender in the singular.

So a female speaker says:

• chciałabym

A male speaker says:

• chciałbym

This is completely normal in Polish and is something English does not do.

Because Polish usually drops subject pronouns when they are already clear from the verb form.

In chciałabym, the ending already tells you the subject is I. So ja is unnecessary unless you want emphasis or contrast.

For example:

• Ja chciałabym pojechać do Hiszpanii, a on do Włoch.
  = I would like to go to Spain, and he to Italy.

Without that contrast, leaving out ja sounds natural.

Pojechać is the perfective verb, while jechać is imperfective.

Here, pojechać is used because the speaker is talking about one complete trip: the idea of going to Spain as a single planned event.

Very roughly:

• jechać = to be going / to go by transport, with focus on the process
• pojechać = to go, set off, make the trip, with focus on the whole action being completed

After chciałabym, Polish very often uses a perfective infinitive when talking about something the speaker would like to do once:

• Chciałabym pojechać do Hiszpanii. = I’d like to go to Spain.

Yes, if you want to be more specific.

• pojechać = go/travel by transport, without focusing on the exact means
• polecieć = fly

So both can work, but they mean slightly different things:

• Chciałabym pojechać do Hiszpanii. = I’d like to go to Spain.
• Chciałabym polecieć do Hiszpanii. = I’d like to fly to Spain.

If the important detail is that you would go by plane, then polecieć is better.

Because do takes the genitive case when it means to in the sense of movement toward a place such as a country or city.

The base form is:

• Hiszpania = Spain

The genitive form is:

• Hiszpanii

So:

• do Hiszpanii = to Spain

This is a very common pattern:

• do Polski = to Poland
• do Francji = to France
• do Anglii = to England

Because many feminine nouns ending in -ia form the genitive singular with -ii.

So:

• Hiszpania → Hiszpanii
• Anglia → Anglii

It may look unusual at first, but it is a normal spelling pattern in Polish.

Yes. Polish word order is fairly flexible, and changing it usually changes emphasis, not the core meaning.

For example, these are all possible:

• Na wakacje chciałabym pojechać do Hiszpanii.
• Chciałabym pojechać do Hiszpanii na wakacje.
• Do Hiszpanii chciałabym pojechać na wakacje.

The original sentence puts na wakacje first, which makes the vacation context the starting point of the sentence. Another version might sound more neutral or put more emphasis on Hiszpanii.

Not exactly.

• Chcę pojechać = I want to go
• Chciałabym pojechać = I would like to go

Chcę is more direct and stronger.
Chciałabym is softer, more polite, and often sounds more like a wish or dream.

So in this sentence, chciałabym gives the whole idea a more gentle, natural tone.