Translation:There are eight people.
It's 8 people ?
Correct as well.
“There are eight persons.” is perfectly correct. No doubt about it!
But " these are eight people" is a no go.
People is not countable. When the counting is used persons should be used.
I'm curious what you're basing this on. See the note here ("Usage") for a summation of the general usage distinction.
Sounds okay to me. If anything, "eight people" sounds more natural than "eight persons."