"Het ontbijt is de eerste maaltijd."
Translation:Breakfast is the first meal.
English and Dutch handle articles in slightly different ways. Meals and other regular daily occurrences are special cases in English but not in Dutch. Normally they would get definite articles like in Dutch because implicitly the context is a particular or prototypical day and we are talking about the unique breakfast of that day. It would be natural to refer to the day's breakfast as the breakfast.
- Breakfast was the day's major event.
- The king's execution was the day's major event.
Dutch is more regular as it uses the definite article in both cases.
Yes, I wonder about this, because all breakfasts are the first meal. This sentence is not like your examples. I would think that Dutch would also omit the article for a generalization, and if it really were a specific breakfast than English would also require it. "The itinerary lists that the breakfast will be at 9 am to accommodate the business men who will be traveling here this morning." As this is a specific meeting and breakfast, the article would be used.
It's not clear that this sentence is necessarily a general statement about all breakfasts, though it's quite likely. I'm a bit out of my depth here, but at least in my native German, in the general statement about breakfast being the first meal of the day the definite article is optional but is used more often than not. I think that's because there is an implicit quantification going on:
[On every day] the breakfast [of that day] is the first meal [of that day].
(Of course that's wrong in English. It is a literal translation from German and presumably also from Dutch.)
In that other sentence the article is missing for a different reason. Note that we can't tell for sure whether it's the definite article that's missing, the indefinite article, or whether it's even about several breakfasts:
- Maybe they stay for a night and get the one breakfast that it makes sense for them to get.
- Maybe upon leaving they are given a single packed breakfast that they can eat whenever they need one in the future.
- Maybe they have booked a week-long stay including breakfast - i.e. including 7 breakfasts.
In ontbijt krijgen (to get breakfast), the object ontbijt (breakfast) has to some extent fused with the verb into an almost phrasal verb that doesn't specify number and definiteness.
Use or non-use of articles exhibits subtle differences between the various European languages and is notoriously hard to explain. All we can really hope for is explanations that make it easier to accept how another language is different than what we would normally expect. Fortunately, using the instincts from one Germanic language when speaking in another always results in something that isn't too outrageously wrong. I doubt there are many good predictive rules that can be used to improve your instincts before you get a feeling for a new language.
But at least it's much easier to learn the differences between various Germanic or Romance languages than to get started with the entire concept of definite articles when coming from a language such as Russian, which doesn't have them.