I’ve taken 3 college level courses on linear algebra and only really got an intuition for eigenvectors/eigenvalues when watching his video series. Super great!
http://setosa.io/ev/principal-component-analysis/
(edit: ugh, contains an ad for MacKeeper)
Incidentally, that particular grammatical quirk is one I've seen a number of times. Is it a thing for people coming from Russian? Or just general difficulty with remembering the order of the two subjects in two-subject phrases?