"Η μικρή κατσίκα είναι δίπλα στην αγελάδα."

Translation: The small goat is next to the cow.

[HK-FTW]

Wondering why this skill has to come so far down the tree...

[DemetriosM2]

My feeling is, for additional vocabulary and a factor of surprise.

[UralMasha]

what's wrong with the "little" goat??

[a1.el.en.1]

Nothing - and it's accepted now.

[Vemund63]

Could I write:
Η μικρή κατσίκα είναι δίπλα σε η αγελαδα(?).
I have learned once that is(είναι) is followed by something called "predikatsord"(predikativ) which is in nominativ.