It's a complicated way of thinking about it. I used to teach it in such a way that it was very easy for students to understand. I would ask them to think of things in major (or more correctly, when speaking about modality, Ionian) then, flat third and seventh, That would make it a dorian scale.
So, D dorian, flatten the F# and C#.
Easy.
I am still stuck upon the idea of the word and more importantly the MEANING and IMPLICATION of the word. Suspension implies a stoppage of movement. In no matter what context... if one is suspended from school, they are stopped from going there. If a lawyer suspends a --->motion<-----, he stops the procedure (as in "to proceed forward").
So, what is the "P"reparation?
What is the "S"uspension?
What is the "R"esolution?
In English, suspension is thought of as a form of verb. Persons who think of it as a chord are using it as a NOUN. Well, the word "suspension" is not a noun. To use it as a noun, they are using the word incorrectly.
Holds watermelon in the air... points at it and announces: "this is a steam locomotive". No, it is not a watermelon. It is a choo-choo train.