Can i say du stämmer for meaning you are correct* (a person, not a sum or an amount)
No, we don't say that.
Vad sägs om du är tätt?
And if it is, Are there other expressions?
Can't say that either, what we normally say is Du har rätt, maybe there are other ways but I can't think of them right now.
Yes, that means like 'that's correct'.
But you can say du stämmer [ett instrument] meaning 'you are tuning [an instrument]' :D
The sum is wrong should be accepted, means same as incorrect
I translated it as "The sum does not match" and got a boom. Is my translation totally wrong?
For the most part, no it isn't technically...hm..
I also used match because of my understanding via Finnish. That said, my understanding could be completely wrong.
what does actually the verb stammer mean here?
Verbs always in second place, right?
Yes, in main clauses that are not questions!
Stämmer is a bit confusing. Correct in English is primarily an adjective - the correct answer. Sometimes as a verb - to correct a problem. Swedish and English dont treat the verb the same way.
Right. stämmer is a verb, but there just isn't a very good English counterpart that is also a verb.
what about 'to tally'?
Like "das stimmt" in German?
Does the sum in this sentence refer to a total or an equation?
can a summa not be an amount when talking about money?
can you say rakingen stammer inte like the bill is not correct for example in a restaurant
now we're getting more to mathematics :)