他已吃过午饭 He has had lunch ; He has dined

午夜过后 After the Midnight ; after midnight

你吃过午饭了没 You had lunch yet

吃过午饭了吗 Eaten lunch yet ; dined

下午晚一点过来 Late in the afternoon

他已经吃过午饭 He has had lunch

我很早吃过午饭 Very early I had lunch

他已经吃过午饭了 He had already eaten lunch ; He has had lunch

我吃过午饭了 I had lunch