Verb conjugation of "zusammenstoßen" in German

I work as an actor in the theater. I have studied English for seven years, French and Spanish for two years. Well, my level of Spanish is too low to have a good conversation, but I understand it.
In school, I had also learned Latin but it's been more than forty years ago. I grew up in Bern and I had lived there all my life, I had no opportunities to travel. It was not that easy during the war.
Thank you for your answer, my English is not very good, but it should be fun to learn together, don't you think? Generally, studying alone is no fun at all. So how do we proceed? How's it going?