Hi Helena,
The way English-speaking people use envy, I would translate that as “benijden” rather than “afgunst”.
Example: “You have got such a nice house! I envy you!”
“Je hebt zo een mooi huis! Ik benijd jou!”
Now. Please note, it’s very unusual to say “Ik benijd jou.” People in the Netherlands would actually say “Ik ben jaloers!” Which translates to “I am jealous”. Even though that’s used in an informal sense. Like Miss Lien & Simon said below.
Also I would not use “afgunst” as a translation for envy, as this has a much more negative connotation & envy is a littttttle more positive than that!