The Passive "se"
In English, we often use the passive voice to emphasize the action rather than who is doing it (e.g., "tickets are sold", "the language is used"). In Croatian, a very common way to express this is by combining an active verb with the short word se.
When using the passive se, the thing being acted upon becomes the grammatical subject of the sentence, and the verb must match it in number (singular or plural).
The Impersonal "se"
You can also use se when there is no specific subject at all, translating to English as "one does something", "they do something", or "people do something". This impersonal structure is heavily used for public signs, local rules, and general customs.
For impersonal sentences, the verb is always in the third-person singular.
Talking About Customs
This impersonal structure is particularly useful when discussing traditions and everyday practices, like whether one leaves a tip or what is traditionally eaten for lunch.
Word Order Reminder
Remember that se is an enclitic, meaning it naturally gravitates to the second position in a sentence or clause. Because it strongly prefers this second position, it will often follow the very first word of the sentence, even if that means splitting up an adjective and a noun!