Verb conjugation of "clash" in English

Work was performed only in June, July, August and September. In October and November, Erik has been waiting for Katja's visit and Sabine was on maternal leave after Christmas and New Year.
I would gladly be your friend, but I must admit that I have little time for learning because of my work. Maybe we can talk now and see how it goes. If it goes well I can return home earlier.
I like music very much too. I prefer classic music, but rock is also good. When you come to my Berlin we need to out to concerts together and visit a few bars. They are all close to the center.