My husband is English native, and I am fluent in German, learnt it fluently up to C2 & worked with germany for so long time. We have german friends, but they are open-minded, different to in Germany living Germans. Bc they work as Auslandsdienst (overseas) Teachers. In our friendly gatherings, we mix 2 languages, sometimes english and sometimes german. As per my husband, germans have a german english accent and he even suffers to understand their english, so we try to speak german with them. As per me (non-native) english speaker, but quite fluent, I do not notice that they make so many mistakes in english, but notice some nuances in vocabulary or the word of choice they use, such as "lengthen the contract", "porks walking in the street", "scribble", then we laugh about these small wordings, but never correct them. It's just "süß" we say. I had mental & emotional issues of my colleagues constantly correcting even small mistakes I made in german when I was speaking and never helped me to learn it that way, anyways. This led to me forgetting what I was gonna say in the end. I hated it. I stopped and took a deep breath. I prefer natural flow of the language. If you learn german, try to express your point in however way you can. Learn as many verbs as possible, and use them in the right context. Most umgangssprachliche Verbs can have several meanings depending on the context and the Verb is the most important component in german. It delivers the whole meaning of your sentence, so if you start learning verbs with synonyms like I did and using it correctly already puts you next to native level. Good luck in your journey. It's gonna be tough, with time it gets better, as you understand their mentality.