Short answer: it is the plural for of "the". Ex: η πάπια (sg.) / Τις πάπιες (pl.)
Grammatical answer: It is the plural feminine accusative article. The articles for feminine nouns are:
Singular: Nominative - η Genitive - της Accusative - την
Plural: nominative - οι Genitive - των Accusative - τις
This sentence appeared in a review session before the accusative case lesson, along a few other sentences with accusative case in them. Also, I got this question wrong because I used nominative for the ducks. In the future, what is a good way to know if the nouns should be in accusative or nominative? Sentences like this lack subject and verb and could be very ambiguous.
I don't understand WHY is "αυτές τις πάπιες" instead of "αυτές οι πάπιες". Maybe τις is accusative?? and οι is nominative? and the sentence is looking for a direct object instead of the subject of a sentence? The only other example is "αυτον τον καφέ" which looks like the answer to a question of "do you want this coffee?" and the answer is: "Όχι, όχι αυτον τον καφέ" No, not this coffee. Could a moderator help me with this??
I don't understand why is "αυτές τις πάπιες" instead of "αυτές οι πάπιες" unless the question is asking for an accusative or direct object instead of a nominative or subject of the sentence. I don't know if "τις" is the accusative for the plural feminine. Could a moderator please help me??
If you check the other comments on this page you'll see this has been answered twice:
In this kind of sentences, you cannot know if accusative or nominative is used. Both could be correct and should be accepted.
The reason that we can use either "οι" nominative used for the subject or "τις" accusative used for the object is that this is not a full sentence. So, we don't know what it is trying to express therefore we accept either one.
Our database only has "τις" if Duo has some mechanical faults we have nothing to do with it. This forum is for language-related discussions. Anything beyond that needs to be reported to:
Της is the genitive singular form of the feminine definite article, while τις is the accusative plural. You can find these and more in the tips section (they're only visible to some app users, so I suggest using the website if you can't see them) and the resources posts in the Greek forum https://forum.duolingo.com/topic/936.
We moderators cannot see your sentence therefore before you make a comment you should have made a REPORT. Then post on the comment page.
Here's how to REPORT.
Go to the bottom of the exercise page where you'll see "REPORT" Click on that: Then choose what you want to REPORT:
-My answer should be accepted.
This is the one you should click on if your translation was not accepted.
After choosing the REPORT you want to make you should post on the comment page.
TIPS TO MAKE LEARNING EASIER + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links.
We have no way to be sure but one that we encounter when the translations correct is the inadvertent use of the wrong keyboard...for example if you had used the Greek keyboard to write the first letter "N" then changed keyboards. While with the naked eye we can't see the difference the program that grades the exercises recognizes them.