Merubah kalimat simpel past tense ke kalimat PPT,PCT,PPCT contoh kalimatnya : They greet the passanger in the lobby everyday

simple past=they greeted the passanger in the lobby last week.
PPT=they have greeted the passanger in the lobby before
PCT=they are greeting the passanger in the lobby now
PPCT=they had been greeting the passanger in the lobby before