Rashi often refers to tzeirei as "kamatz katan" and segol as "patach katan". Why? In what sense are they smaller versions of kamatz and patach?
I understand that kamatz and tzeirei are תנועות גדולות, while patach and segol are תנועות קטנות, which has some consequences for sheva na and dageshim. Rashi's classification is going in a different direction. Does it also have grammatical consequences?
Tenuah gedola Tenuah ketana Rashi big Kamatz Patach Rashi small Tzeirei Segol