Republic of [South] Korea 2:0 Greece the Koreans get a B+ for doing what they had to and maintaining dominance once they had it; the Greeks get a D and brought shame and disgrace upon their team for generations to come; and the officials get an A- for maintaining invisibility.
Nigeria 0:1 Argentina both teams get a B- for allowing the match to deteriorate into 1v1 and 2v2 duels with little sense of "team" out there; the officials get a B+ for a slightly better than servicable effort.
England 1:1 United States England gets a B- for tactical naïveté and for an inept central defense that was lucky to emerge without giving up three goals; the US gets a B+ for not folding after giving up yet another early goal, but no more than that for not taking advantage of first-half dominance after the early goal; and the officials get a B for not losing control of the match, despite a number of small (fortunately, non-decisive) errors that were pretty obvious.
As usual, the UK papers are busy focussing on their goalkeeper's gaffe without admitting that the US should, with better finishing, have won this one. Green gave up one he shouldn't have... and saved one he shouldn't have. Meanwhile, Ricardo Clark's tendency toward momentary lapses of concentration demonstrated that he just can't be trusted in the US central midfield against top-quality sides. If you look at the moment before the critical move, every serious English chance on goal (including the goal itself) came through Clark's man slipping free and/or area of responsibility being vacated.