Questions & Answers about De moeder is heel blij met het gedrag.
How would this sentence change to use the "er + preposition" structure we are currently learning?
If you wanted to say "The mother is very happy that he behaves well", you can't put the dat (that) clause directly after the preposition met. Instead, you use the anticipatory er and combine it with met to form ermee (which usually splits). The sentence becomes: De moeder is er heel blij mee dat hij zich goed gedraagt. The er ... mee points forward to the dat clause!
Why is it heel blij instead of hele blij?
Here, heel is an adverb meaning "very," and it modifies the adjective blij. Adverbs do not get an -e ending. If heel were used as an adjective modifying a noun (meaning "whole" or "entire"), it would get an ending, as in de hele dag (the whole day).
In English I might say "happy about the behavior". Is it always blij met in Dutch?
Yes! In Dutch, the fixed preposition for being happy about or pleased with something is met (with). You will consistently use blij met for objects, situations, or people.
Is there a rule that explains why it is het gedrag (neuter) instead of de gedrag?