mopperen Learn Unstarted Summary The Dutch translation for “to grumble” is mopperen. Practice Lesson "to grumble" Practice (1) Lesson Learn Lesson words to grumble etc. View all lesson words Lesson phrases This lesson has no phrases. Themed Courses Miscellaneous 395 Part of Speech Courses Verbs (all parts) 102 Verbs (infinitives) 47 Acknowledgements Audio Leslie Van Ael