Learn Hardcore Czech: Na nádraží hledám tabuli, která ukazuje, kdy přijede náš vlak. - At the station I am looking for the board that shows when our train will arrive.

v nádraží would literally mean inside the physical building/structure of the station (and is basically never used). For the general location at the station, the natural phrase is na nádraží.

What case is nádraží in, and why does it look the same as the basic form?

Nádraží here is in the locative case after the preposition na.

Neuter nouns ending in -í (like nádraží) have the same form in several cases:

Nominative singular: nádraží
Accusative singular: nádraží
Locative singular: nádraží

So even though na requires the locative here, the word’s form does not change. You have to recognize the case from the context and the preposition.

Could I also say Hledám tabuli na nádraží? Is the word order Na nádraží hledám tabuli important?

Both sentences are grammatically correct:

Na nádraží hledám tabuli
Hledám tabuli na nádraží

The difference is in emphasis:

Na nádraží hledám tabuli starts with na nádraží, so it emphasizes the place (at the station, I am looking for a board).
Hledám tabuli na nádraží is more neutral; it just states what you are doing and where.

Czech word order is relatively flexible. Information that is already known or being contrasted often comes earlier; new or emphasized information tends to come later.

Why is there no pronoun já? Why not Já na nádraží hledám tabuli…?

In Czech, subject pronouns (já, ty, on, etc.) are usually dropped, because the verb ending already shows who the subject is.

hledám = I look for / I am looking for
hledáš = you look for
hledá = he / she / it looks for

So Na nádraží hledám tabuli is the normal way to say At the station, I’m looking for a board.
You would include já only for emphasis or contrast, for example:

Já na nádraží hledám tabuli, ale on hledá pokladnu.
I at the station am looking for a board, but he is looking for the ticket office.

Why is it tabuli and not tabule?

Tabule is a feminine noun. In this sentence it is the direct object of hledám, so it must be in the accusative singular.

Declension of tabule (singular):

Nominative: tabule (the board – subject)
Genitive: tabule
Dative: tabuli
Accusative: tabuli (the board – object)
Locative: tabuli
Instrumental: tabulí

So after hledám you need the accusative: hledám tabuli.

Does tabule really mean the kind of board/sign you see at stations, or is there a more specific word?

Yes, tabule can mean a board or signboard, including information displays.

In a station context, you might hear:

informační tabule – information board
odjezdová tabule – departures board
příjezdová tabule – arrivals board

Your sentence with just tabuli is fine and understandable: people will imagine the main information board. If you want to be very specific, you could say for example:

Na nádraží hledám odjezdovou tabuli.
At the station, I’m looking for the departures board.

Why is it která and not some other form of který? What is která doing here?

Která is the relative pronoun meaning which / that and it must agree with its antecedent, tabuli, in:

gender: feminine (like tabule)
number: singular
case: nominative, because in the relative clause it is the subject of ukazuje

Structure:

tabuli, která ukazuje…
the board which shows…

Inside the clause, you can ask:

Who/what shows? → která (that board) → subject → nominative feminine singular.

Other forms (for comparison):

Masculine animate: který
Neuter: které
Feminine accusative: kterou, etc.

In this context, která is the only correct form.

Why do we say která ukazuje and not something like a single word meaning showing, like an English showing board?

Czech can form participles, but it does not normally use them in the same way as English does for noun phrases like a board showing….

Instead, Czech typically uses a full relative clause with který / která / které:

tabule, která ukazuje… – the board that shows…
vlak, který jede do Prahy – the train going to Prague

There are verbal adjectives like ukazující, but tabule ukazující, kdy přijede náš vlak sounds bookish or artificial in everyday speech. The natural, neutral form is the relative clause tabule, která ukazuje….

Why is it kdy přijede náš vlak and not když přijede náš vlak?

Kdy and když both relate to when, but they are used differently:

kdy – in questions (direct and indirect) asking about a point in time
- Kdy přijede náš vlak? – When will our train arrive?
- Nevím, kdy přijede náš vlak. – I don’t know when our train will arrive.
když – in time clauses meaning when / whenever (not a question)
- Když přijede náš vlak, nastoupíme. – When our train arrives, we will get on.

In your sentence, kdy přijede náš vlak is an indirect question (something like: that shows when our train will arrive), so kdy is required, not když.

Why is it přijede and not přijíždí? Both look like forms of přijet / přijíždět.

Czech distinguishes between perfective and imperfective verbs (aspect):

přijet – perfective, focus on a single completed arrival
- present form přijede = will arrive (future meaning)
přijíždět – imperfective, focus on ongoing or repeated arriving
- present form přijíždí = is arriving / arrives (regularly)

We are talking about one specific future event: the train’s arrival according to the timetable. For that, Czech prefers the perfective verb:

kdy přijede náš vlak – when our train will arrive (at what time it will pull in)

kdy přijíždí náš vlak would typically mean something like:

When does our train usually arrive? (e.g. every day according to a timetable)
Or: At what time is it currently arriving? (more about the process)

So for a single scheduled future arrival, přijede is the natural choice.

Why does přijede look like a present tense form if it means will arrive?

For perfective verbs in Czech, the present tense forms usually refer to the future.

přijede (from přijet) – he/she/it will arrive
udělám (from udělat) – I will do (it)
napíšeš (from napsat) – you will write (it)

There is no separate future auxiliary for perfective verbs. You only use být (budeš, budou, etc.) to form the future of imperfective verbs:

přijíždět → bude přijíždět – will be arriving / will arrive repeatedly

So kdy přijede náš vlak is literally a grammatical present form, but aspect makes its meaning future: when our train will arrive.

Can I change the word order and say …kdy náš vlak přijede instead of …kdy přijede náš vlak?

Yes, both are grammatically correct:

kdy přijede náš vlak
kdy náš vlak přijede

The difference is subtle and mostly about rhythm and focus:

kdy přijede náš vlak is the most neutral and common order.
kdy náš vlak přijede can put a tiny bit more emphasis on náš vlak, contrasting it with other trains (for example, when many trains are mentioned).

In normal conversation, both will be understood the same way, and learners are generally safest with kdy přijede náš vlak.