For questions about the special word order adjective + indefinite article ("a" or "an") + noun, as in the sentences "You're too good a friend" or "How big a problem will that be?"

English adjectives usually come after the indefinite article a/an, as in the sentences "You are a good friend" or "That is a big problem."

But in some sentences, the adjective comes before the indefinite article: "You're too good a friend" or "How big a problem will that be?"

This has been called the "big mess construction".