5 Best Complex Sentence Generators

By Editorial Staff •  Updated: 09/06/23 •  Teaching Tools

Grammatically speaking, a complex sentence is simply a sentence that contains at least one independent clause and one dependent clause. A complex sentence generator simply helps you rewrite sentences, sort of like a paraphrasing tool.

We think the confusion comes down to the search intent behind people looking for complex sentence generators. While from a grammar perspective, a complex sentence is one thing, most native speakers would simply want to find a tool that can help make a generic, boring sentence more complex with a better selection of vocabulary.

What is a complex sentence generator?

Complex sentence generators utilize various linguistic rules, algorithms, and, in some cases, machine learning techniques to create sentences with diverse structures, incorporating elements such as subordinate clauses, conjunctions, and varied syntactical arrangements.

These tools aim to mimic human language’s intricacies by producing sentences beyond simple structures, offering a nuanced and sophisticated expression of ideas.

The sentence we will be using in this example review

For this review, we will be using a few different generators and will be using the same sentence each time to keep things fair. Our sentence will be a proper complex sentence with an independent and dependent clause:

“Brian was happy to have ran in the race, even though he didn’t win.”

Jasper AI – The best professional writing assistant tool

This the writing tool we use here at Teach and GO to help us create student feedback, write rough draft essays and help out with blogging aspects like creating good meta descriptions and compelling titles.

While not a replacement for hiring a competent writer or doing the writing yourself as a professional, it is a seriously big help and tool we think is essential for any teacher needing to write essays, research papers and more.

So, how did Conversion AI do? Let’s find out:

Jasper AI for the win. This rewrite happened at the click of a button. If you did not like what came out you simply click the blue button to make it try again. But this rewrite is great. It’s better than the original but not over the top with overly verbose language. What’s even better is that Conversion AI allows you to rewrite entire paragraphs, not just sentences.

It also comes with a content improver, paragraph generator, sentence expander, intro and conclusion paragraph creator as well. Overall, we find this AI writing tool to make writing easier and less mentally taxing.

From long-form teacher reports, essays for professional education, blog posts, and more, we’ve found Jasper AI to be incredibly helpful.



Jasper AI

An AI writing assistant that speeds up your writing. A great choice for any teacher looking to write faster and easier. Easily paraphrase sentences and paragraphs at the click of a button. Create content faster and more easily than ever before.

Chat GBT – The powerful free option

Chat GBT from Open AI is going to revolutionize content creation. It’s a powerful tool where you can input commands to the AI to create sentences, paragraphs, stories and even write code. When using Chat GBT it is essential you give it prompt commands so it knows what you want it to do.

The GPT models are built upon the Transformer architecture, a neural network architecture that excels in processing sequential data. What sets GPT apart is its pre-training approach. Before fine-tuning for specific tasks, GPT models undergo extensive training on vast amounts of diverse text data, allowing them to learn contextual relationships, grammar, and semantics.

For this example we asked the AI to “rewrite” the sentence as a prompt so the AI would know to rewrite a complex sentence.

Here is how it performed:

A very good output from Chat GBT. It makes sense, is still complicated enough and it is a unique take. If all you’re looking to do is quickly rewrite sentences and paragraphs using the rewrite prompt function should be acceptable enough for most uses cases.

The only issue is you need to understand how to use prompts to get it to write something unique because it will paraphrase in the same exact way any paragraph or text you give it. It’s not like you’re going to get a unique piece of content compared to someone else.

However, if you’re looking for something free that’s quick and easy you can’t go wrong with ChatGPT.

Our favorite prompt to get started rewriting and paraphrasing a piece of text is:

“Please paraphrase [insert content]”

You can obviously expand on this prompt to your liking with adding in how the content should be presented, they types of words used as well as the specific audience you’re paraphrasing for.

Quillbot – The classic rewrite tool

When it comes to online generators and writing tools, Quillbox is a free browser-based tool that tends to show up whenever there’s discussion about online writing assistants.

It has a good reputation for being one of the more user-friendly generators, and it’s definitely one to consider. Best of all, it’s totally free to use. So how does this perennial option stack up?

Fantastic results out of Quillbox. In particular, we like how they keep updating and improving this tool for writing complex sentences. Now you can adjust the style of writing from creative to formal as well as adjust the synonyms. Though that last feature is locked behind a paywall.

One thing to also mention about Quillbot is that it does support multiple languages including French, German and Spanish.

CS Generator – An acceptable free Option

CS Generator is usually one of the top 3 sites that will pop up when you go looking for “best complex sentence generator” and for good reason. It makes a boring sentence more complex with better vocabulary.

Take a look at the results we got below:

Overall not bad for a free tool. We liked the use of the word “jubilant” and “albeit” which are two under used words as a way to express emotion. As you can see, CS Generator simply rewrote the sentence and swapped out some words.

For a free tool where you need to rewrite a sentence or two it’s a solid choice, but if you’re needing a lot more power and flexibility then we strongly suggest checking out Conversion AI (also known as Jasper).

Google Bard – AI rewrite

Finally, we have Google Bard, Google’s answer to Chat GPT. It’s a learning model AI and can perform simple and complex tasks with ease. Google Bard is free to use, all you need to do is agree to the terms of service and sign in with a Gmail account.

BERT’s “bidirectional” encoding excels in understanding the nuanced meanings of words within the context of a sentence, making it valuable for tasks requiring a deep understanding of language. BERT can be applied to extract essential information from a given text and generate concise and contextually relevant summaries.

Finally, BERT’s bidirectional approach generates diverse and contextually appropriate paraphrased sentences, which is valuable in applications such as content rewriting.

So how did Bard do?

Outstanding, it gave multiple responses. All are detailed, complex but maintain the original idea.

These sentence all convey the same as the original meaning and we like how Google explains in detail the process and theory that went into each sentence rewrite to help you understand.

Complex sentence generators conclusion

In conclusion, complex sentence generators are teeming with innovation and possibilities. The tools mentioned in this blog post represent a glimpse into the vast landscape of language generation.

Whether you are leveraging the power of OpenAI’s GPT-3 for its versatility, exploring the depth of Google’s BARD in understanding context or harnessing the linguistic analysis capabilities of NLTK, or Jasper AI as your robot writing assistant for your staff of teachers, each tool has unique strengths you’ll find useful.

Jasper AI

An AI writing assistant that speeds up your writing. A great choice for any teacher looking to write faster and easier. Easily paraphrase sentences and paragraphs at the click of a button. Create content faster and more easily than ever before.

Editorial Staff

I'm David Unwin and I head the editorial staff here at Teach and GO. I've taught as an ESL teacher in Thailand for 5+ years at all levels of education, from elementary to University. I was also one of the first 1000 VIPKID teachers. I and my team now share my extensive experience as a teacher here at Teach and GO. Learn more.

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