Pronunciation of шесть Why is the "е" in "шесть" pronounced "e" instead of "ie" as usual? Спасибо!

Uses of tenses "I don't know what I should have said" "I don't know what I would have said" "I didn't know what I should say" "I didn't know what I would say" "I didn't know what I should have said" "I didn't know what I would have said" Are they all right? Thank you very much!

Umst. I found this "Umst." on DB BAHN website. I know the verb "umsteigen", but what's the noun related to this verb? Danke.

Is it correct? I found it on the internet. Is that correct? "I'm keen on listening to music as well of reading". I don't understand the use of "as well of". Maybe it's a typo. Let me know. Thanks in advance. :)

A short story I want to tell you about what has happened to me this morning. I was walking along the street when I saw an old friend of mine. It was a long time since I didn't meet him, so I was pretty surprised at seeing him. Suddenly, I remembered my whole childhood, how beautiful it was to live in the '80s, and how happy we were those years. We didn't have smartphones, tablets and, above all, internet. We played outdoors and we weren't afraid of strangers like children are today. Maybe we were too bold, but we learnt how to live quickly, we experienced life since we were very young. It was as if our parents had given us kinds of antibodies to recognise bad people. That's all for today. I hope you enjoyed my short story. Have a nice day!

A short story Excuse me if I bother you, but I want to tell you about what has happened to me this morning. I was walking along the street when I saw an old friend of mine. It was a long time since I didn't meet him, so I was pretty surprised at seeing him. Suddenly, I remembered my whole childhood, how beautiful it was to live in the '80s, and how happy we were in those years. We didn't have smartphones, tablets and, above all, internet. We played outdoors and we weren't afraid of strangers like children are today. Maybe we were too bold, but we learnt how to live quickly, we experienced life since we were very young. It was as if our parents had given us kinds of antibodies to recognise bad people. That's all for today. I hope you enjoyed my short story. Have a nice day!

Nie etwas/je etwas Are "Keiner von euch versteht nie etwas hier" and "Keiner von euch versteht je etwas hier" the same? I'd like to know if "je" and "nie" are interchangeable. Danke!

kaffeinlosem? "Er ist mit einem Paket kaffeinlosem Kaffee angekommen". Should it be "koffeinlosem"? I've never heard of this word before and I can't find that in my dictionary. I know "koffeinfrei" instead. I don't understand...

Und mir nicht? "Der Lehrer hat Martin eine gute Note gegeben und mir keine gute". Can I write "und mir nicht" instead of "und mir keine gute" or is that wrong? Danke :)