Edit: this seems to be the consensus over at the Swedish section of WordReference back hinein Feb of 2006 Let's take your example:One-on-one instruction is always a lesson, never a class: He sometimes stays at the office after work for his German lesson. After the lesson he goes home. Notice https://youtu.be/T0zWXvhEQwo?si=wNc6ihu97ShtIl7u