Relearn VS learn again

Solution 1:

In a comment, John Lawler wrote:

Essentially this is the difference between transitive learn, where it's the apprehension of the specific knowledge that matters -- learn Spanish, learn piano, learn shorthand, and intransitive learn, where it's the process of learning itself that's being discussed, irrespective of topic. Learn again cuts off the possibility of an object, so it's clearly intransitive; relearn is ambiguous between transitive and intransitive, and that's the reason one might prefer learn again. However, in this context, cannot learn, unlearn, and relearn is clear enough in intent.