Completely free AI tools are rare, but partially or limited-use AI tools such as ChatGPT (free version) and Google Bard (free version) can be beneficial. However, it's essential to proofread any content generated by AI when using it for educational purposes.
Additionally, you may want to check out this resource: "19 Best AI Tools for Students in 2024 (Mostly FREE)." Here’s the link: https://kripeshadwani.com/best-ai-tools-for-students/
IYH Dear Fatema Alalyan DuckDuckGo offers access to four free anonymous AI application within their browser https://duckduckgo.com/duckduckgo-help-pages/aichat/
"It currently supports Anthropic’s Claude 3 Haiku, Mistral AI’s Mixtral 8x7B, OpenAI’s GPT-4o mini, and Meta’s Llama 3.1 70B (built with Llama). Each model relies on unique algorithms and data sets and will respond to your prompts differently. You can use DuckDuckGo AI Chat to get answers to questions, compose an email, summarize text, or just have an interesting conversation."
The drawback is small context sizes between 1500 and 3000 words per session maximum, but I find it sufficient for most everyday tasks.