I could be wrong, but I thought it was Er läuft, with the umlaut over the A and not the U. Let me make this correction with the disclaimer that I have only completed German 101, but I did get 100% on my final. 
And to be pedantic 2½ years after the fact, it would actually be Er läuft. And AFAIK, you have to have an article in there, leaving either “Er läuft zu der Schule,” or “Er läuft zur Schule.”
And I’ve always used laufen for “run” and spazieren for “walk”.
As to the OP’s question, I always heard there was some king who rudely called his (individual) subjects “you” even though he should have said “thou” (“thee”?) and eventually, that caught on.
Cliff