Since 2016 we offer Dutch lessons for adults at the American School of The Hague, location Wassenaar.
Morning and afternoon classes on various levels as well as Dutch Book Reading.
Look under "courses".
New courses on various levels starting as from January 2022.
Sign up on the ASH website under Life at ASH / Parent Teacher organization /
Adult Education, 
or sign up on the Dutch for Expats website under "courses".
Courses are also open for non-ASH parents.