Questions & Answers about Mijn eigen robijn is gestolen.
Why is the verb is used here when the translation says "has been"?
This sentence uses the present perfect passive voice. In English, we use "has been" + past participle ("has been stolen"). In Dutch, the auxiliary verb for a completed passive action is zijn (to be). Therefore, is gestolen means "has been stolen." If you used wordt gestolen, it would mean the theft is happening right now.
Because robijn is a de-word, shouldn't eigen get an -e ending?
The adjective eigen (own) is a strict exception to the normal adjective inflection rules. It almost never takes the -e ending, regardless of the noun's gender or the article used. It will always remain uninflected, as in mijn eigen, zijn eigen, or het eigen.
How does this sentence relate to the dative constructions we are currently learning?
While this sentence uses a standard possessive pronoun (mijn), you could theoretically express this with a "possessive dative" structure to emphasize the personal impact on the victim: Mij is een robijn gestolen (Literally: "To me a ruby has been stolen"). However, the standard possessive used in this sentence is much more common in everyday speech.
What would the word order be if I started the sentence with Gisteren (Yesterday)?