Flemish is a slight variation of Dutch, some words differ similar to Spanish and Catalan.
The written forms of Flemish and Dutch are almost identical, but the spoken dialects can differ quite widely – enough to make comprehension difficult.
The two forms are closer than Castilian and Catalan Spanish, but perhaps as different as Lowlands Scots and standard English.
The Flemish are certainly hospitable. I hope they remember our visit for its good behaviour.