Questions & Answers about Oni znów czekają na pociąg.
Both mean again or once more and are interchangeable in most contexts.
– znów is slightly more formal or written.
– znowu is more colloquial.
Word order and emphasis can be identical: Oni znów czekają… vs Oni znowu czekają….
The verb czekać (to wait) requires the preposition na + the accusative case to mean “wait for.”
pociąg is a masculine inanimate noun whose accusative singular form is identical to its nominative: pociąg. You know it’s accusative because of the preposition na.