Learn Hardcore Croatian: Prošli vlak nije stigao na vrijeme. - The last train did not arrive on time.

In this sentence, prošli vlak most naturally means “the previous train,” i.e., the one before the current one being discussed. If you want “the last/final train (of the day),” say:

posljednji vlak (neutral/formal) or
zadnji vlak (very common in speech).

You can also say prethodni vlak for “the previous train,” which is unambiguous and formal-ish.

Why is it stigao (masculine) and not stigla or something else?

Because vlak is a masculine noun, and Croatian past participles agree with the subject in gender and number. Examples:

Masculine singular: vlak je stigao
Feminine singular: linija je stigla
Neuter singular: vozilo je stiglo
Plural: vlakovi su stigli (masc. mixed), autobuse su stigle (fem. plural), vozila su stigla (neut. plural)

What tense is nije stigao, and how is it formed?

It’s the Croatian perfect (compound past). Formation:

Auxiliary of biti (to be) in 3rd person: je
Past participle: stigao
Negation attaches to the auxiliary: ne + je → nije So affirmative would be: Prošli vlak je stigao na vrijeme.

Why is nije placed after Prošli vlak? Could I start with Nije?

The short auxiliary (je/nije) is a clitic and prefers the “second position” in the clause. In Prošli vlak nije stigao..., the first prosodic unit is Prošli vlak, so nije comes next. Starting with Nije is possible if you front the negation for emphasis (e.g., answering a question), but neutral word order places (ni)je after the first element:

Neutral: Prošli vlak nije stigao na vrijeme.
Emphatic: Nije stigao prošli vlak (na vrijeme).

Why use stići (arrive) instead of doći (come)?

Both can work, but:

stići (perfective) focuses on the arrival at a destination (very natural for vehicles).
doći is broader (“to come/arrive”), also fine: Vlak nije došao na vrijeme. Another very common alternative is to describe lateness directly: Vlak je kasnio.

What’s the difference between stići and stizati?

Aspect:

stići = perfective (“to arrive” as a completed event): nije stigao (did not arrive on time on that occasion).
stizati = imperfective (“to be arriving / to arrive habitually”): nije stizao na vrijeme implies repeated or ongoing failure to be on time (habitual/iterative).

Does “didn’t arrive on time” necessarily mean it was late? Could it have been early?

Literally, nije stigao na vrijeme means it was not on time—so it could be early or late. In practice, it usually implies lateness. To be explicit:

Late: Vlak je kasnio.
Early: Vlak je došao ranije.

What case is used in na vrijeme, and why?

It’s accusative after na because this is an idiomatic time expression meaning “on time.” vrijeme is a neuter noun, and neuter singular nominative and accusative look the same, so you don’t see a form change. Note: Croatian uses na vrijeme; Serbian typically has na vreme (ijekavian vs. ekavian).

Is vlak the same as voz?

They mean “train,” but differ by standard:

Croatian: vlak (standard)
Serbian/Bosnian: voz (standard) Croatians understand voz, but vlak is the norm in Croatia.

Why is the past participle from stići spelled stigao with a “g”?

Stem alternation: stići has the present stem stign- (e.g., on stigne), and the past participle uses that stem: stigao (m.), stigla (f.), stiglo (n.), stigli (pl.). This is regular for this verb, even if it looks irregular from the infinitive.

Any pronunciation tips for the tricky parts (vlak, stići, stigao, vrijeme)?

vlak: starts with a consonant cluster; the “v” is a light labiodental approximant (between English v and w).
stići: “ć” is a soft “ch” sound; say roughly “STEE-chee.”
stigao: three syllables “STI-ga-o,” not “stigo.”
vrijeme: the “ij” makes a y-like glide: roughly “VRYE-meh.”

Could I rewrite the sentence with a different word order?

Yes, to shift emphasis:

Vlak nije stigao na vrijeme. (neutral, drops “prošli”)
Na vrijeme prošli vlak nije stigao. (emphasizes “on time,” marked/poetic)
Nije prošli vlak stigao na vrijeme. (fronted negation/focus) All remain grammatical; the original is the most straightforward with “previous train” as topic.

How do I say “The previous train also didn’t arrive on time / Neither did the previous train”?

Use ni for “nor/neither” in negatives:

Ni prošli vlak nije stigao na vrijeme. You can also say: Prošli vlak također nije stigao na vrijeme, but ni is more idiomatic for “neither.”

Are there alternative ways to express the same idea?

Common options:

Prošli vlak je kasnio. (The previous train was late.)
Prethodni vlak nije došao na vrijeme.
Posljednji vlak nije stigao na vrijeme. (if you really mean the final train of the day)