Translation:De koe is schoon.
Alternative: De koe is proper.
I'd argue "Schoon" would be more quickly attributed to something looking pretty, whereas 'proper' only exists in the context of cleanliness.
If you have alternatives you'd like to suggest, please use the "report a problem" function during the lesson:
On the other hand, it's useful for us non-natives to be aware of these nuances.
Gotcha. Thanks for the heads up.
Why does a cow have a masculine definate article when it is a female animal?
De is masculine and feminine. Het is neuter.