Terrific examples, Selcen! Sometimes I sit down to try to plow through a couple of your modules, and it can be sheer maddening agony. But now that I've reached Negation and Infinitive, I'm getting at least some sense of how mature thought is expressed.
Before now, I've felt stuck in "The cat is going from the house to the garden". I mean, what kind of conversation starter is that?;-)