Verb conjugation of "charge" 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.
Could you please read the following offers in a critical manner and confirm it before I will send it? I have also mentioned the warranty and the software in the offer, because it was requested by the customer.
I am glad you know, I have learned Czech and my English is also not that bad, but we could speak in German. I got your message and I want to apologize again. Next time I will do it more accurate.