Verb conjugation of "clone" 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.
Everything in your letter is perfect! Almost no errors and the writing style, very impressive! After this first year in England, you have also improved your vocabulary and the grammar skills.
I really would like to invest more time here but until now I was too busy to keep my promises. Maybe I should take a vacation and go back to Scotland and take another language course there.