Awful is listed in the Merriam Webster Unabridged New World Dictionaries of 2003 and 1992 published by Barnes & Noble in conjunction with Random House as only an adverb and an adjective, but not as a noun. The mistaken impression that it is a noun leads to the concept of the predicate word, without which the impression creates erroneous sentence fragments. For example: “The thing is awful.” “The thing is awful” is a fragment of a sentence! As an adverb, awful is defined in the same meaning as “awfully”; and the sentence could be rephrased as “The thing is extremely.” As an adjective, awful is defined as dreadful; and the sentence could be rephrased as “The thing is dreadful.” In the adjective form, dreadful is a noun, but awful was an adjective, however, since dreadful is also an adjective the listener makes the connection by itself. If the thing is to be the subject of the sentence and it is to be modified by the adjective, then the sentence could be rephrased as “The awful thing is.” and that would be a response to a question rather than a statement. As a statement “the awful thing is” is not a complete sentence.
It is worth knowing that the world “awful” has a completely English etymology, so it should not be confused with the Dutch word “afval” that means “waste” in English.