Can I choose the topic of the texts I write?

There is no topic selector: texts are chosen automatically to fit the keys of your level, which is what makes the exercise useful. What you can choose is the practice language in Settings, and you can have up to three active at the same time.

The closest thing to choosing a topic is the Marathon, which works with thematic texts from a wide catalog: you get a different topic each game, although you cannot choose it.

The reason is pedagogical: in the learning levels, the text must contain the keys you are practicing and avoid the ones you don’t know yet. If you could freely choose the topic, the exercise would stop teaching what it needs to.