However, a translation into English is a derivative work. The copyright belongs to the modern translator. As of 2025, that is legally available for free.
If your goal is to access the content of Kitab al-Ayn without reading the classical Arabic, you have better luck with later dictionaries that relied heavily on Al-Farahidi’s work: Kitab Al Ayn English Pdf
What makes the English translation of Kitab al-‘Ayn a "solid feature" in the world of linguistics is not just the content, but the way it demystifies Al-Khalil’s genius. The PDF format allows English readers to navigate the author’s radical departure from traditional organization. Unlike modern dictionaries arranged alphabetically, Al-Khalil organized words based on phonetic properties—starting with the deepest throat sounds (the letter 'Ayn') and moving outward. However, a translation into English is a derivative work
Al-Khalil ibn Ahmad al-Farahidi (718 – 786 CE) was a philologist, poet, and grammarian from Basra, Iraq. He was also the mentor of the famous Sibawayh, the founder of Arabic grammar. Al-Khalil’s genius lay in his systematic approach to language. Before his time, Arabic vocabulary was recorded haphazardly. Al-Khalil introduced a scientific method. If your goal is to access the content