In English, reciprocal verb constructions are created with “each other,” e.g.,
“They see each other.”
“We write each other.”
In Italian, they are created with the plural reflexive pronouns ci, vi, si and the appropriate plural form of the verb, e.g.,
Si telefonano ogni giorno.
They call each other every day.
Vi scrivete spesso.
You write each other often.
Quando i miei genitori si sono visti, si sono baciati.*
When my parents saw each other, they kissed (each other).
Paolo e io ci siamo sentiti qualche giorno fa.*.
Paolo and I spoke (to each other) a couple days ago.
*Past participle agreement follows the same rules detailed above for reflexive verbs in the past.