Questions & Answers about Mi ne scias, kiom malfrue li alvenos.
Because scii means to know a fact, piece of information, or answer.
Koni means to be acquainted with or to know a person, place, or thing through experience.
Here, the speaker does not know some information: how late he will arrive. So scii is the correct verb.
- Mi scias la respondon = I know the answer.
- Mi konas lin = I know him.
Here kiom means how much / to what degree. In this sentence, it is being used with malfrue to mean how late.
So kiom malfrue literally means something like to what degree late.
This is a very normal Esperanto pattern:
- kiom rapide = how quickly
- kiom longe = how long
- kiom forte = how strongly