Can you paint enamel over latex?

Enamel is a Word used to describe a finish, not the formulation of a paint. It simply means a hard reflective surface. Many people mistakenly use the Word enamel when referring to oil based paints.

So. if you are asking if you can paint latex or acrylic paint over a latex or acrylic enamel the answer is yes, however, I strongly recommend you sand the old paint first to give the top coat "tooth".

If you are asking about painting latex or acrylic over an oil based paint the answer is still yes, however you must first sand the old paint and apply a good quality primer to it. Check with a reputable paint retailer for the best brand in your area.