"The man eats chicken."
Translation:Ο άντρας τρώει κοτόπουλο.
Each word needs to be learned individually, Duo uses each new word several times in a lesson so you can get used to the spelling. One very important hint is that the first person in the present tense.... e.g. I have έχω , I see βλέπω, I drink πίνω etc always ends with ω. The word I (Εγω) isn't even needed.
Ο άντρας τρώει το κοτόπουλο = the man eats the chicken
The exercise only says κοτόπουλο, without an article. That means that the man eats chicken in general or that he is eating some chicken.