Learn Hardcore Czech: Na její narozeniny se vždycky těšíme, protože se zdá, že je ten den všechno možné. - We always look forward to her birthday because it seems that everything is possible that day.

In Czech, narozeniny (birthday) is a so‑called pluralia tantum – a noun that is always used in the plural form, even when it refers to just one birthday.

So:

její narozeniny = her birthday
moje narozeniny = my birthday
k narozeninám = for (my/your/etc.) birthday

There is no natural singular form like *narozenina in normal modern usage. English uses a singular, but Czech simply treats this concept as plural.

Why is the preposition na used in na její narozeniny? Could I say something else?

With time expressions, na + accusative often means on the occasion of / for (a special day/event).

na její narozeniny = for her birthday / on her birthday (as an event/occasion)
na Vánoce = for Christmas
na Nový rok = for New Year’s (Day)

You could also see:

o jejích narozeninách (locative with o) – more like on her birthday (at that time), a bit more neutral / descriptive.

In this sentence, na její narozeniny emphasizes the occasion (the celebration) that we look forward to, so na is very natural here.

What case is její narozeniny in, and why?

Narozeniny here are in the accusative plural after the preposition na.

Preposition na can take accusative when it expresses direction, aim, or occasion.
The structure těšit se na něco (to look forward to something) always uses na + accusative.

So:

těším se na její narozeniny – I’m looking forward to her birthday.
těšíme se na dovolenou – We’re looking forward to the holiday.

Její is the possessive pronoun her and agrees with narozeniny in gender/number/case (feminine plural accusative).

Why do we say se těšíme? What does se do here?

Těšit se na něco is a reflexive verb in Czech. The se is part of the dictionary form and cannot be left out.

těšit se na něco = to look forward to something

It’s similar to how some English verbs just require a preposition (e.g. depend *on something). In Czech, some verbs require *se as part of their normal form.

Compare:

těšit (someone) = to please / to make somebody happy
- To mě těší. – That pleases me / I’m glad to hear that.
těšit se na = to look forward to
- Těším se na víkend. – I’m looking forward to the weekend.

So se here is lexical (part of the verb’s meaning), not optional.

Why is se also used in protože se zdá? Is it the same se as in se těšíme?

It’s the same word se, but it plays a different role here.

In těšit se, se is part of a reflexive verb with a specific meaning: to look forward to.
In zdá se, se is used in an impersonal/reflexive construction to mean it seems / it appears.

So:

Zdá se, že… = It seems that… (literally: “se-seems that …”)
There is no explicit subject like it in Czech; se helps create this impersonal meaning.

You can add an experiencer:

Zdá se mi, že… = It seems to me that…

So both use se, but:

těšit se – lexical reflexive verb
zdát se – often impersonal with se, like it seems

Why is the verb order že je ten den všechno možné and not že ten den je všechno možné?

Both že je ten den všechno možné and že ten den je všechno možné are grammatically correct. Czech word order is flexible, especially inside subordinate clauses.

The choice here is mostly about rhythm and emphasis:

že je ten den všechno možné
The verb je comes earlier; you get a smooth flow: that (it) is that day (that) everything is possible.
že ten den je všechno možné
Slightly stronger emphasis on ten den (that particular day), because it’s placed right after že.

In spoken Czech, že ten den je všechno možné might sound a bit more neutral, but the original order is still very natural and idiomatic.

Why is the adjective možné and not možná after všechno?

In Czech, adjectives must agree in gender, number, and case with the noun they describe.

všechno = everything
- grammatically: neuter singular, nominative
Therefore the adjective must also be neuter singular, nominative: možné.

Examples:

všechno dobré – everything good
všechno nové – everything new
všechno možné – everything possible

Možná is the feminine form, so it would not agree with všechno.

What is the function of ten den here? Why not just všechno je možné without it?

Ten den = that day. It specifies when everything seems possible.

všechno je možné – everything is possible (in general).
ten den je všechno možné – on that day, everything is possible.

You could also rephrase with a preposition:

v ten den je všechno možné – literally in that day everything is possible = on that day…

The original ten den (without v) is a time adverbial in the accusative, which is very common in Czech to express “that day / every day / next week” type meanings:

každý den tam chodím – I go there every day.
příští týden přijedu – I’ll come next week.

Why is there a comma before protože in Czech?

In Czech, subordinate clauses introduced by conjunctions like protože (because), když (when/if), že (that), etc. are almost always separated by a comma from the main clause.

So:

Na její narozeniny se vždycky těšíme, protože se zdá, že je ten den všechno možné.

Structure:

Main clause: Na její narozeniny se vždycky těšíme
Subordinate clause: protože se zdá, že je ten den všechno možné

Unlike English (where the comma before because is often omitted), Czech punctuation rules require it here.

Could I say Vždycky se těšíme na její narozeniny instead? Is there a difference?

Yes, you can absolutely say:

Vždycky se těšíme na její narozeniny.

Both:

Na její narozeniny se vždycky těšíme.
Vždycky se těšíme na její narozeniny.

are correct.

Differences:

The verb cluster se těšíme must stay in the second position (clitic rule: se wants to be very early in the sentence).
The element you put at the beginning (Na její narozeniny vs. Vždycky) gets slight emphasis.

Nuance:

Na její narozeniny se vždycky těšíme – emphasizes her birthday as the topic.
Vždycky se těšíme na její narozeniny – starts with always, a bit more neutral for an English ear.

But both are very natural.

Why is the verb těšíme in the present tense when it refers to future birthdays?

Czech often uses the present tense to express habitual or repeated actions, even if they refer to the future in a general sense.

Na její narozeniny se vždycky těšíme.
= We always look forward to her birthday (every year, whenever it comes).

It describes a general habit, not a single future event. This is similar to English:

On her birthday we always look forward to it (also present simple for a general habit).

If you wanted a clear, one‑time future idea, you’d say:

Na její narozeniny se budeme těšit. – We will look forward to her birthday (this time).

Could I say těšíme se na její narozeniny instead of Na její narozeniny se vždycky těšíme? Does the se have to be in that position?

Yes, you can say:

Těšíme se na její narozeniny.

About se:

se is a clitic, and in Czech clitics tend to appear in second position in the clause.
In Těšíme se na její narozeniny, the first stressed element is Těšíme, so se naturally comes right after it.

In Na její narozeniny se vždycky těšíme:

The first stressed group is Na její narozeniny, then comes se as the clitic.

So you will not normally start the clause with Se těšíme na…; that sounds wrong. The usual patterns are:

Těšíme se na její narozeniny.
Na její narozeniny se těšíme.
Vždycky se těšíme na její narozeniny.

All follow the clitic‑in‑second‑position rule.

What is the difference between zdá se and vypadá for “it seems / it looks like”?

Both can sometimes be translated as seems, but they’re used differently:

zdá se, že… = it seems that…
- more abstract, often about impressions, assumptions, feelings
- Zdá se, že je ten den všechno možné. – It seems that everything is possible that day.
vypadá, že… / vypadá to, že… = it looks like…
- more visual / surface appearance, though it can be more general in speech
- Vypadá to, že bude pršet. – It looks like it’s going to rain.

In this sentence, zdá se is better, because it’s about a general feeling that everything is possible, not just something you can literally see.