This is the 2363rd most frequent Swedish word.
ert
"Your" (plural or formal).
Here, 'ert' functions as the possessive pronoun for 'your,' addressing a group formally in the context of ownership of the umbrella.
Har ni glömt ert paraply?
Have you forgotten your umbrella?
In this sentence, 'ert' indicates possession, referring to the work accomplished by the addressed group or entity formally.
Läraren berömde ert arbete.
The teacher praised your work.
Here, 'ert' conveys possession regarding the visit experienced by the addressees, showing politeness in addressing them.