For 16 years, Grammarly has meticulously honed its grammar editing software to reflect natural English language patterns. Now, the company is leveraging artificial intelligence to expand similar capabilities to five additional languages: Spanish, French, Portuguese, German, and Italian. According to Grammarly’s VP of Enterprise Product, Luke Behnke, this expansion addresses the platform’s “number one feature request” since its founding.
Beyond Spelling: AI-Powered Sentence Rewriting
Grammarly’s AI doesn’t just catch spelling errors. It also reworks sentences and paragraphs to match the tone of native speech, improve clarity, and enhance overall readability now available in six languages, including English. Users can also translate these core languages into 19 additional languages without leaving the platform, streamlining workflows that previously required multiple tools.
The expansion comes amid growing competition in AI-based multilingual software, with Google Search’s AI Mode adding more languages and Apple introducing live language translation in its latest AirPods.
Grammarly’s AI Approach
Grammarly has always incorporated machine learning into its software, describing its original proofreading tool as an “agent” possibly the first AI agent widely used for writing assistance. The integration of large language models (LLMs) began in 2023, utilizing open-source LLMs fine-tuned by Grammarly’s team of analytical linguists.
Despite the broader language support, Grammarly did not proportionally scale its linguist teams. Instead, a smaller group of experts, combined with internal evaluations and user feedback, helped fine-tune grammar and style suggestions in the new languages. These models are hosted on Grammarly’s own infrastructure, under strict security controls and training rules.
Beta Rollout and User Adoption
In the beta rollout, which reached about a million users, native speakers of the five new languages accepted Grammarly’s suggestions at rates comparable to English users. Some users were surprised when familiar red underlines appeared in their native language, highlighting spelling errors and style suggestions.
Grammarly also offers users the option to integrate third-party LLMs, including those from major AI companies like OpenAI, for advanced features. While third-party models cannot train on user data, Grammarly’s own models do although enterprise and education customers have training disabled by default, with other users able to opt out.
Looking Forward
Though Grammarly has not publicly disclosed which languages might come next, Behnke notes that customer support teams worldwide have requested additional language support, particularly in regions with offshore call centers. This expansion aligns with Grammarly’s broader ambition to evolve into a comprehensive AI productivity platform, further cemented by its acquisition of the email application Superhuman and the launch of nine AI agents for students and educators.
By combining AI, linguist expertise, and user feedback, Grammarly continues to push the boundaries of multilingual writing assistance, making it easier for millions of users worldwide to write clearly, correctly, and confidently.
