How to get normals per vertex, not per face?

When getting the normals from a mesh, it returns an array of normals of each face, is there a way to do by vertex? I mean, return an array of the normals in order of vertex?

is there an extension from a a mesh vertex? like mesh.vertices[10].normals? or another way to obtain the normal?

EDIT: Ok, wait a second.. mesh.normals is per vertex? why does it return a much larger array than the mesh.vertices array of the same mesh?