David N. answered 06/18/19
Experienced tutor in Math as well as Spanish.
When using, "de nada", one can use it in a formal or informal setting. However, when using the phrase "no hay de que", it is often used in an informal setting. For example, using the phrase "no hay de que" is the equivalent of using "no problem" in English. It means "you're welcome" but it can be said in different ways.