Se dicen vs Se dice
This seems rather obvious, but I am making sure of it: what is the difference between "se dice" and "se dicen" ??
Doesn't it have to do with the number of things you are talking about?? For example, "Se dicen que estas cosas son buenas".... as opposed to "Se dice que eso era bueno"
3 Answers
I beg to disagree with Eddy. "Se dice" is an example of the passive/impersonal se construction.
Your examples, kelar, are not comparable to each other:
Se dicen que estas cosas son buenas. = They are telling each other that these things are good. (This form is reflexive.)
Se dice que eso era bueno. = It is said that that was good. (This is impersonal.)
There is a passive se construction, though, that agrees with the number of the object & subject.
Ex: Se vende computadora. Se hablan español e inglés aquí. The object & the subject are the same, "computadora" and "español e inglés", respectively.
The other construction uses the 3rd person plural + que.
Using your own example: Dicen que estas cosas son buenas. They say that these things are good.
That said, you cannot use "se dicen que" to express the passive voice.
No, it is referring to whom is doing the "saying", ie, a single person or more than one person. It has nothing to do with wether the item they are talking about is singular or plural.
Se dice - One says
Dicen - They say
Edited: 18:28
It depends on whether the phrase indicates passive voice or an impersonal or unknown subject.
For example, se abren las ventanas is passive voice = the windows are open. In that case, since ventanas is plural, the verb is plural.
The impersonal se is similar to what we say in English when we speak about "they" but we don't have anyone particular in mind. Se habla español en esta tienda.