Verb conjugation of "darken" in English

Dear Maximilian, I look forward to your visit in Switzerland. After a somewhat difficult start, it seems that we have increased the website traffic and we are starting to receive more visitors.
On the frozen lake, you can skate, but I would never dare it because it is far too dangerous. Who knows how thick the ice really is and how accurate the measurements are. It can break.
I wish you lots of fun and success in your French class, and a nice weekend with lots of snow. PS: I am so happy I found you, my Italian friend, because we can visit each other all the time now.