English Translation
It’s almost perfect.
Whatever the “it” is in this example, it must be a masculine noun.
e.g. the “it" being the corridor:
(Ο διάδρομος) είναι σχεδόν τέλειος (m)
What if the it was a female noun? e.g. the “it" being the kitchen:
(Η κουζίνα) είναι σχεδόν τέλεια (f)
What if it was a neuter noun? e.g. the “it" being the living room:
(Το σαλόνι) είναι σχεδόν τέλειο (n)