Was ist die richtige Grammatik? "Er ist schon gekommen." oder "Er ist schon gekommen"?

Manchmal erschwert das Einfügen eines Adjektivs (in diesem Fall "bereits") die Sichtbarkeit der Verbstruktur.

Wenn der Satz wie folgt umformuliert wird:
#color(white)("XXX")#Er schon ist gekommen.
es ist leichter zu sehen Gegenwart perfekt Tempus. (Beachten Sie, dass das "Perfekt der Gegenwart" trotz seines Namens a Vergangenheit action tense).

Es gibt 3-Vergangenheitsformen (siehe Anmerkung unten) (in englischer Sprache):

#{:
("simple past:","independent action completed in past", " | ","He came."),
("present perfect:","action completed before now"," | "," He has come."),
("past perfect:","action completed before some other action in the past"," | ","He had come.")
:}#

In addition to these main forms there are also past progressive forms for ongoing actions in the past:

#{:
("simple past progressive"," | ","He was coming."),
("present perfect progressive"," | ","He has been coming."),
("past perfect progressive"," | ","He had been coming")
:}#