The alvenis sounded to me like two words, al venis. This illustrates how one works backwards from knowing words to figuring out what sounds people are making. Alvenis is not at well known word status in my brain yet.
I have always arrived at night
I find it impossible to hear whether it is mi and ni in this soundbite
Once your ear is used too it, it starts becoming easier to hear the difference.
Iam via orleo estas kutimiĝi al ĝin, ĝi iĝas pli faĉila a aŭdi la diferenco.
Me too, I have sometime problems between them. I must train my ear.
When I read "nokte", I think "nightly" because it's an adverb and that translation feels natural.
For "at night", I want to say "dum nokto" or something similar.
If "nokte" is "at night", what is "nightly"?
nokte = at night, maybe during several night, maybe each night.
ĉiunokte = nightly, each night.
en la nokto = in the night (at a given point, hour), en ĉiu nokto.
dum la nokto = during the night (entire duration), dum ĉiu nokto.