SE

Impersonal SE and Passive SE

A. The Impersonal SE

se + third-person singular verb

The impersonal SE (SE impersonal) is used with a third-person singular verb to express the impersonal. English subjects one, you, people (in general), or they.

Será difícil tener una sociedad justa si se considera a ese grupo étnico como inferior.	It will be difficult to have a just society if you consider that ethnic group inferior.
Se dice que la comunicación y el respeto mutuo son la clave.	They say that comunication and mutual respect are the key.
Algunos quieren cambiar la visión negativa que se tiene de esta comunidad.	Some want to change the negative view that people have of this comunity

Here, the use of SE indicates that people are involved in the action of the verb, but no specific individuals are identified as performing the action.

B. The Passive SE

SE + third person {singular or plural} verb + noun

Noun + SE + third person {singular or plurarl} verb

The passive SE (SE pasivo) is very similar to the impersonal SE. As with the impersonal construction, the agent of the action is either unknown or unimportant. The speaker simply wishes to communicate that an action is being done. The verb is in the third person singular or plural, depending on whether the thing acted upon is singular or plural.

Entre algunos gitanos españoles se hablan el español y el caló.	Among some Spanish gypsies, Spanish and Caló (gypsy dialect) are spoken
Se utiliza el caló cuando es conveniente guardar secretos.	Caló is used when it is useful to keep secrets

En resumen

- In both the empersonal and the passive constructions, SE indicates that there is no specific agent or doer of the action

- In both constructions, the verb is singular or agrees with the direct object. If the direct object is plural, the verb is plural; otherwise, it si singular.