Passive voice SE: sing. vs. plural

Question

The rule indicates: If the object is singular the verb should be singular, and if the object is plural the verb should be plural.

BUT, what is the reasoning behind this:

-Se abre los fines de semana. -Se acepta tarjetas de crédito.

HELP PLEASE, I need to explain this to my students!

Answer 1

Here se abre refers to the thing that is open - such as a store - and not to the weekends.

:) - Kiwi-Girl, Feb 27, 2014

Yes. La tiende, el restaurante.. whatever. - annierats, Feb 27, 2014

Answer 2

JC is quite right.

If you'd like to brush up on the uses of se you may find this article helpful.