Trink(e)! -> informal, addressing one person
Trinkt! -> informal, addressing more than one person
Trinken Sie! -> formal, addressing one or more people
This has more actual speech connotations. In German, as we have read so far, words do not roll over the tongue. Instead we have the pauses and stops because words end in t/d and emphasis... basically pronunciation stuff.
Spoken German tends to blur these lines somewhat to make the sentences nicer to hear.
This is just an observation, don't take my word for it.
Imperative Singular should be ""trink", not "trinke" right?
Both are possible.
E.g. "Lauf schnell!", not "laufe schnell"
Those are also both possible.
But verbs that change their vowel only have the version without the final -e: essen only has iss! and not esse! or (even worse) isse!, at least in the standard language.
I would recommend using the versions without the final -e, though; they sound more natural to me in most cases.
Falscher Imperativ von "trinken"!
Laut Duden ( https://www.duden.de/rechtschreibung/trinken#rechtschreibung ) sind sowohl trink! als auch trinke! richtig.
When she speaks for us to type in German, the first fast version says Trink (like a command); and when I hear it that clearly... I don't need to hear the slow, and the fast is WRONG! And grrr, I got it wrong! I hate that I have to remember she says it wrong, rather than having them fix it. I reported it; but....