"How" and "why" are very different. "How" deals with factual descriptions, explanations, ways, and extent. "Why" deals with reasons and motives.
When these words are used as adverbs, you must pay attention to which word they modify. Here are some examples:
A1 How is the village beautiful?
A2 How beautiful is the village?
B1 Why is the village beautiful?
B2 ???
In A1, "how" modifies "is". The question asks for an explanation of the way in which the village *IS* beautiful. You cannot answer that question by saying "It is very beautiful". Possible answers are:
"The village is beautiful because of its flowers and churches."
"The village has lovely architecture."
In A2, "How" modifies "beautiful". The question asks the extent of the village's beauty. You cannot answer this question by saying "The village has many flowers in bloom." Possible answers are:
"The village is very beautiful"
"The village so beautiful that it deserves to be photographed"
Next, let's consider the "why" question. All answers to B1 should provide reasons or motives for its beauty. Here are some possible answers to B1:
"The village is beautiful because its citizens cherish cleanliness"
"The village is beautiful because it was carefully planned by an architect"
"The village is beautiful because its government places a high priority on keeping it that way"
B2 is left blank because it is nearly impossibly for "why" to modify a word, like "beautiful", that is not related to reason or motive.