The phrase "about which I learnt" is not correct in standard English.
The correct form would be "about which I learned." You can use it when referring to a subject or topic that you have gained knowledge about, typically in a more formal context.
Example: "The book discusses various historical events about which I learned a great deal during my studies."
Alternatives: "that I learned about" or "which I became knowledgeable about."
With all the tennis on, PatLux recommends an early Lionel Shriver, Double Fault: Whenever I watch grand slam tennis I think of the lives of the lower ranked players about which I learned much when reading this novel about life on the circuit.
This week's segment of CBS Doc Dot Com examines sexual addiction, a subject about which I learned absolutely nothing in medical school and have not learned much more since.
I was offered the chance to specialise in this area with a master's at the University of Wales, Swansea, during which I learnt about those algorithms that are borrowed from the sphere of artificial intelligence to solve the more complex problems.
The second was homeopathy from which I learnt a lot about what actually is disease and what actually is cure!
I had a chat with Gilbert about BillFloat yesterday, in which I learned more about the company and its plans in the payment services space.
I began to read about the Beatles: my mom's book "Shout!," in which I learned about everybody's relationships; my dad's copy of "The Book of Rock Lists," which he had won from a radio station, and which I read with interest in a green velvet scoop chair at his apartment.
I found out about this tragedy two days after it happened, on a Sunday afternoon, in a way that sort of typifies the manner in which I learn about most things these days.
At the same time, I went on to become an investment partner at Dorm Room Fund, a $500,000 venture fund focused on investing in student-run start-ups in which I learned about venture capital, investing, and start-ups.
What followed was years of sexual development during which I learned a lot about myself and my body.
It was the saddest I have been about a poet's death since the death of James Merrill, in 1995, which I learned about, also upon waking, from the NPR broadcast that served as an alarm on my clock radio.
I like to visit a Web site called Thoughts on the Dead, which I learned about from my colleague Nick Paumgarten.
