Depending on context, which does not exist in this sentence, "They had lost your keys." is just as valid as "They had lost their keys."
It could even be "they had lost his/her keys.
"sus" refers to the keys (llaves) and is plural because "llaves" is plural.
If the sentence was:
They had lost their (or your, his or her) key. It would translate as:
Ellas habían perdido su llave.
It's technically valid, but for that you'd be more likely to say "Ellos habian perdido las llaves de usted".
I'm a native Spanish speaker, and let me tell you, that you MUCH more likely to say "su(s)" instead of "de usted", it sounds out of place and IRL nobody uses it ("de usted").
I'm dying of curiosity. ¿If you're a native Spanish speaker, why are you "learning" Spanish with DuoLingo?
"They had lost your keys" is correct, But it means "sus llaves (de usted)",, and "their keys" means "sus llaves..(de ellos), so it changes the owner of the keys.
It isn't wrong, but why take the chance on that translation with HAL the DL computer when "Ellas ... sus" would most commonly be combined in a "They...their" sentence construction in real life?
So this would be describing the past situation? In other words, "They have lost their keys" is not a valid translation?
Yes. It is 'had', not 'have'. It's the 'past in the past'. 'Yes, I would have called from their house, but they had lost their keys, so instead I went home.'
Because that means "they HAVE lost their keys" when the past perfect is "HAD lost their keys."
que es la diferencio en el contento de este palabra entre "had" y "have" ayuda por favor
La diferencia es que "had" significa el pasado. Es una acción completada y terminada. Es perfecto pasado. "Have" se refiere al pasado también, pero el pasado reciente y aún puede afectar el presente. Es un perfecto presente. Por ejemplo: "Yo había estudiado anoche" significa que el estudiar ha terminado, la acción es completada. Pero, "He estudiado anoche", no dice que el estudiar es completado, El estudiante puede estar estudiando todavía..
The difference is that "had" means the past. It is an action completed and finished. It is past perfect. "Have" refers to the past as well, but the recent past and can still affect the present. It is a present perfect. For example: "I had studied last night" means that the studying is over, the action is complete. But, "I have studied last night," does not say that the studying is complete, The student may still be studying.
Under the haber verb, under the conjugation it says the past tense is habieron not habian. Which is it? Apparently habian (with the accent). Then their conjugation is wrong? Or am I missing something.
The translations for had aren't había and so forth, it's haya hayas haya hayamos hayáis hayan
I put her keys which is apparently wrong, I thought sus meant his, her, its, your usted or Their ustedes, how the hell can you tell from reading the sentence which translation of sus to use?
you are correct. "sus" can translate as:
any of these choices should be correct since there is NO context in this sentence.
You should report it