Theory
Write an Equivalent
Determine Perspective
100
Distinguishes Systemic from Non-Systemic meanings
Bull's Tense System
100
They have changed the address three times already.
Han cambiado de dirección tres veces hasta la fecha. 
100
Ellas cambian de opinión muy seguido.
PP simultaneus
200
The meaning Each category has within the overall system
Systemic Meanings
200
They studied English in an academy for two years.
Estudiaron en una academia de Inglés por dos años.
200
My grandma will prepare a nice meal on Saturday
PP posterior
300
Which are the three orientations or perspectives speakers adopt  according to Bull's theory
Anterior, Simultaneus, and Posterior
300
She surfed almost every weekend.
Surfeaba casí todos los fines de semana.
300
His mother has trusted him in spite of his mistakes.
PP Anterior
400
Includes specialized functions it has acquired outside the system by way of extension, and the two languages diverge in this case. 
Non-systemic Meanings
400
Mike said he would sell it for a decent price.
Mike dijo que lo vendería a un precio aceptable/decente.
400
I hadn't realized until I got there.
Rp anterior
500
It is a matter of what speakers wish to say, how they choose to express it and the point of view they select; it is not equitable with real-world time. 
Tense
500
 It seems like we will have graduated by 2022.
De acuerdo a mis calculos, nos habremos graduado antes del 2022.
500

Si ayer no hubiera llovido, mi familia y yo habríamos ido a la playa.

AP from RP 
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