Questions & Answers about Hann bakaði þeim stundum glaðning.
Why is þeim in the dative case here?
This is the dative of advantage (dativus commodi). It shows who benefits from the action, similar to saying 'for them' in English. When you do a favor or perform an action for someone, like baking them a treat, that beneficiary takes the dative case.
What case is glaðning and why?
Glaðning is in the accusative case because it is the direct object of the verb bakaði (it is the thing being baked). The dictionary form is the masculine noun glaðningur, which drops its -ur ending in the accusative. It translates to a treat or a pleasant surprise, and comes from the adjective glaður (glad or happy).
Why is the adverb stundum placed between þeim and glaðning?
I recognize the root stund (a while or period). How did it become the word for 'sometimes'?
Stundum is actually the dative plural form of the noun stund. While it originally meant 'at times', it became fossilized in the language and is now used simply as the standard uninflected adverb for 'sometimes'.