Definition of a Sentence Fragment. Sentence fragments are groups of words that look like sentences, but aren't. To be a sentence, groups of words need to have at least one independent clause. An independent clause is any group of words that contain both a subject and a verb and can stand on its own.
In literature, an allusion is an "unexplained reference to something or someone outside of the text". The reference is usually to someone or something popular, like Mark Twain.
