Breakdown of Si è tessuto al telaio per tutto il giorno.
essere
to be
il giorno
the day
per
for / in order to / because of
a
to / at
Questions & Answers about Si è tessuto al telaio per tutto il giorno.
Why is the auxiliary è used here? Doesn't the verb tessere (to weave) normally take avere?
Since si here means "people" (plural), why doesn't the past participle end in -i (tessuti)?
Because there is no direct object in this sentence. When an impersonal si sentence does not have a direct object receiving the action, the past participle defaults to the masculine singular ending -o.
What would happen to the verb if a direct object were added, like "the carpets" (i tappeti)?
If there were a plural direct object, the structure would change to the "si passivante" (passive si). The auxiliary and the past participle would then have to agree with that plural object, making it: Si sono tessuti i tappeti al telaio.