"Αυτό είναι ένα ζωντανό κοτόπουλο."

Translation: It is a live chicken.

[Clem.Fandango]

I answered this with "alive" rather than "live", i.e. "it/this is an alive chicken", but it's marked incorrect. I thought alive/live were both synonymous adjectives.

[cjbrewer]

I don't think they're synonymous. "That chicken is alive", but "That is a live chicken". You certainly wouldn't say "That chicken is live" (you can say "that wire is live", but that's a different meaning).
I'm not sure I can quite explain how they're different figures of speech, somebody else will be able to.

[lakottis16]

I thought κοτόπουλο was always used to refer to chicken that you'd eat as opposed to a live animal (similar to beef vs. cow in English). Is it used for the live animal too?

[joe_t4]

Κότα = hen
Κοτόπουλο = domestic fowl / hen especially young, also the meat thereof (who likes eating old birds!).
Chick = newly hatched baby hen (fluffy and yellow).

[SandraGerd1]

the same adjective in male and female version if somebody could tell?

[troll1995]

No, it's ο ζωντανός, η ζωντανή, το ζωντανό.

[ClareSmith26]

If the chicken is alive, it is called a hen in English!

[jaye16]

No, a "hen" is a female "chicken" or other bird. See this from Oxford

Dictionary

noun
1.
a female bird, especially of a domestic fowl.

2.
a female lobster, crab, or salmon.

From Oxford

[VanessaGor47801]

I agree, Clare. If you keep them, you call them either hens OR chickens, both are correct in English usage.

[Y4HQ3]

why is "living" wrong?

[Craig163996]

I'm sure a few lessons back I got marked wrong for writing 'it' for 'αυτό and the reason was in the comments as being 'αυτό' means 'this' and not 'it'.

[jaye16]

I'm sure a few lessons back I got marked wrong for writing 'it' for 'αυτό and the reason was in the comments as being 'αυτό' means 'this' and not 'it'.

"Αυτό" can mean "it, this, that".

"a few lessons back"

How are we to know which lesson you are referring to and whether it actually said that?

[Vemund75118]

Αυτο είναι ενα ζωντανο κοτοπουλο.

[DaRichta]

what is a "live chicken" ??? Sorry, to me that's not english at all !!

what should it mean ? it's not broadcastet?? or what ?

[mizinamo]

what is a "live chicken" ??? Sorry, to me that's not english at all !!

It is.

what should it mean ? it's not broadcastet?? or what ?

That it's alive. Living. Not dead.

Meaning 1 of https://www.oxfordlearnersdictionaries.com/definition/english/live2_1 , not meaning 2.

We don't say "an alive animal"; we say "a live animal" instead.