This

ένας

énas

(known (thing) that the speaker does not think is known to the audience)

αυτός

aftós

(the (thing) here)

αυτός

aftós

(known (thing) just mentioned)

αυτός

aftós

(known (thing) about to be mentioned)

ετούτος

etoútos

(the (thing) here)

ο εξής

o exís

(known (thing) about to be mentioned)

τούτος

toútos

(the (thing) here)

αυτή

aftí

(the thing, item, etc. being indicated)

αυτό

aftó

(the thing, item, etc. being indicated)

αυτός

aftós

(the thing, item, etc. being indicated)

αύτη

áfti

(the thing, item, etc. being indicated)

ούτος

oútos

(the thing, item, etc. being indicated)

τούτο

toúto

(the thing, item, etc. being indicated)