An error in the message after completing a lesson

[Macjory]

I finished a lesson in 'Medicine' (in French), and was told I had just strengthened 'Infinitives.'

[Deliciae]

The 'Medicine' lesson you did probably contained a word or two previously taught in the 'Infinitives' skill, causing it to strengthen when you translated them correctly. Working as intended, as far as I know. :)