Translation:He eats a tomato.
i spelled tomato with a capital T and i got it wrong .
tomato isnt a proper noun so it is grammatically incorrect
tomato is not a proper noun, so with a capital T is grammatically incorrect
So did i
Why not et?
Some words take "et" and some take "en". It's difficult to know if a word takes en or et, but This post has some good links (including "Determining the Gender of a Noun")