Can you substitute milk for half and half?

It really depends on the recipe and the needed consistency. In most cases, half&half or even whole milk can be substituted for light cream to make a recipe healthier. If the recipe calls for heavy cream, it's really a judgment call. You might try a halved recipe with half&half to test before making a full batch.

Substituting half&half or milk in a recipe calling for sweet (whipping) cream is generally NOT recommended.