How can they be distinguished, then?
The Greek grammar shows how.
Kecharitomene is a Greek perfect, passive, participle, which could literally be translated "having been graced," since the root of the word is "charis", which means grace. Ephesians 1:6, which refers to Jesus Christ, uses the aorist, active, indicative echaritosen, meaning "He graced."
Note the difference between Mary, passive voice, "she received grace"; Jesus, active voice, "He graced." This is due to the fact that Jesus is a Divine person; Mary is a human person, a creature, a handmaid.
In Luke 1:28 "Kecharitomene" is nominative or titular, since it follows the greeting "Chaire" ---"Hail [name or title] --- thus the name would normally be capitalized in English translations.
The unique feature of "Kecharitomene" is that it is in the Greek perfect tense, denoting that the state of grace began in past time, by a completed action (hence "fully" accomplished), whose results continue in the present. A more detailed but more suitable translation to denote all these features might be "Fully-Graced One." The Greek passive voice denotes that Mary received the title from an outside source, in this case, ALmighty God.
With me so far?
The New Testament uses the Greek "pleres charitos" ("full of grace") to describe Jesus (John 1:14) and Stephen (Acts 6:8), but these usages are not as specific as to time, agent and continuity as "Kecharitomene".
This is the only place in the Bible --- the only place in all of Greek literature ---where this word is used as a form of address. It's unique. It doesn't make her equal to God (passive voice: it's been done unto her) and not identical to what's said of Stephen, because it's
This unique neologism Kecharitomene is the best Greek word that could have been invented by Divine inspiration to indicate Mary's sinlessness, her being equipped to play her role as the natural source of Christ's human nature, His flesh: human, yet untainted by sin. No other Greek formulation could have conveyed it all.
Smart Archangel, that Gabriel.
Ephesians 1:6 to the praise of his glorious grace, which he has freely given us in the One he loves.
I understand your intense desire that Luke 1:28 include some illusion to "full of grace" but it does not.
>>by a completed action (hence "fully" accomplished),<<
Fully accomplished does NOT mean "full of". I have explained that to you in the past. If I finish putting a 100 bushel wagon load of grain into a 1000 bushel bin I have fully accomplished unloading that wagon. It also means it's been done in the past. It does NOT mean the bin is full.
Mary receiving grace which was naturally in the past since the angel was already there telling her she had received grace in no way indicates she was "full of grace" once again. The term "full of grace" is once again a twisting of words by the Catholic Church to insert justification for their belief.
If the Holy Spirit had intended to indicate that Mary was "full of grace" as He clearly did for Stephen, He would have included the word pleres as He did for Stephen.
Finally, the greeting Chaire is a a primary verb; to be "cheer"ful, i.e. Calmly happy or well-off; impersonally, especially as salutation (on meeting or parting), be well -- farewell, be glad, God speed, greeting, hall, joy(- fully), rejoice. [http://biblehub.com/strongs/greek/5463.htm].
past (the state of grace completed in past time), I already unloaded the corn.
perfect (a completed and accomplished action), I completely unloaded that 100 bushel load of corn.
continuing (its results continue into the present), The load continues to be unloaded. I do not have to do it again.
nominative (name/ title bestowed by an outside agent, in this case, God.) I was the one who unloaded the corn, it did not unload itself.
Now, you didn't attribute the source of your post so I would guess it's from the Catholic Church itself rather than an impartial source. In that can I assume you care not about impartial sources for fear of finding truth?