"No se puede". You can´t do it- It's impossible to do it-
"No se requiere". It's not required
"No se usa- It's no used.
"No se traduce"- It's not translated.
"Se" is a pronoun with a variety of uses.
Paradigmatic or reflexive : alternate with other personal pronouns (me/te/nos/os).
- Direct complement - Instead of "Ie".
Le dio el regalo a Juan. Se lo dio.- He gave the gift to John. He gave it to him.
- Direct/Indirect complements:
Se miraban mutuamente. They looked at each other.
Se peina. He combs.
-in "middle" sentences with animate or inanimate subjects:
Juan se debilitó (con la enfermedad). Juan got weak (with the disease).
Juan se aburre.Juan get bored.
-with reflexive verbs:
Arrependirse, quejarse, avergonzarse, sonrojarse... get repent/complain/ashamed/blush ...
-With verbs that can be constructed with reflexive pronouns and without them:
Dormir / dormirse- Sleep / get asleep
Ir / irse- Go- get going
Other usages (impersonal constructions):
Aquí se vive bien- Here, life is good
Se venden pisos- Apartments for sale.