Complex Sentence Generator - Paraphrase Sentences. Complex Sentence Generator is a free content rewriter that can potentially rephrase, reword, paraphrase and/or rewrite sentences, paragraphs, articles, content, words and/or phrases into a more complex, unorthodox or convoluted alternative while delivering the same meaning. The vocabulary of this sentence paraphraser contains an abundance of rarely used words/phrases and can paraphrase sentences in a variety of ways that are chosen randomly. Aside from this software being used as a paraphrasing tool, it can also be used as a vocabulary improvement tool. The artificial intelligence of this paraphrase generator is so sophisticated that it is capable of understanding context.