To describe a general activity or lively atmosphere without specifying exactly who is doing the action, use an impersonal passive. This is common when talking about festivities and cultural traditions.
The impersonal s-passive
In Swedish, even intransitive verbs (verbs that don't take a direct object, like "dance" or "cheer") can take a passive form. Use the dummy subject det (it/there) followed by the verb's s-passive form (usually adding -s).
This construction often translates to "There is [activity]" or "People are [activity]ing" in English.
| There is dancing and singing at the carnival. | Det dansas och sjungs på karnevalen. |
| There is cheering when the parade passes. | Det jublas när paraden passerar. |
Word order
Because Swedish is a V2 (verb-second) language, if you start a sentence with a time, place, or adverbial phrase, the verb must still take the second position. The dummy subject det then shifts to the third position, immediately following the passive verb.
| During the holiday, there is partying all night. | Under högtiden festas det hela natten. |
| According to tradition, there is toasting in the park. | Enligt traditionen skålas det i parken. |
Combining activities
You can string multiple impersonal passive verbs together to paint a vivid picture of a celebration.
| There is partying and toasting in front of the fireworks. | Det festas och skålas framför fyrverkeriet. |