Disjunctive conjunctions link two elements expressing separation, difference or alternative. They are o, u, ya, bien, sea que , etc.

Let's look at some example sentences.

¿Vamos al zoológico o al museo?
Do we go to the zoo or to the museum?

Julia comprará una blusa azul o roja.
Julia will buy a blue or red blouse.

Sea que no tenga dinero, o sea que no le guste, de todos modos, no lo compra.
Whether he doesn't have any money or he doesn't like it, he won't buy it anyway.

Una vez por semana voy al cine o al teatro.
Once a week I go to the movies or the theater.

Sea que no lo entiende, sea que no quiere entenderlo.
Whether he doesn't understand, whether he doesn't want to understand.

Note: When the following word starts with o we replace it with u:

Yo tengo siete u ocho cosas que hacer hoy.
I have seven or eight things to do today.