Hello. So why is "We have already eaten dinner." translated to "Wir haben schon zu Abend gegessen." while "We have already eaten lunch." is "Wir haben schon Mittagessen gegessen."?
Can I say instead "Wir haben schon Abendessen gegessen." for dinner? Is there another to say the we've eaten lunch that refers to the time of day?
"We have already eaten lunch." can perfectly be translated to "Wir haben schon zu Mittag gegessen." That's what I prefer (being a native German speaker). "Wir haben schon Abendessen gegessen." or "Wir haben schon Abendbrot gegessen" is correct for "We have already eaten dinner." To me "Abendessen gegessen" and "Mittagessen gegessen" sound slightly odd because of the double "-essen". But it is not wrong at all. And if you like to rhyme ... :-)
I think "already" is redundant in engish sentence. "We have eaten lunch" means the same.
In "have already eaten," it does sound redundant. In "already ate," it adds necessary emphasis/connotation.
After straining my brain a bit too much, I've decided that the weird part is "we have," as opposed to "we've." So, although "already" may be logically redundant, "We've already eaten lunch" is a perfectly normal English sentence. (I think.)
Normally yes, but I think we can find cases where emphasis makes a difference. Consider 'we have just eaten' vs. 'we have already eaten'. I see a difference, that is, two cases. 'I have eaten' may indeed be correct but it is less specific in time than either.
Because "ate" is simple past which does not fit to the "have" which is present perfect. You must write: "I have already eaten". You would never write "I have went home" (instead of "gone home") or "I have took the car" (instead of "have taken"), would you?