The problem comes from English: 'Your dad doesn't read a book' means he never reads books, there's an implied 'even' in the 'a', or, if you will: 'Your dad doesn't read (even) a (single) book', and the present tense here has the same value as in 'I play football'. On the other hand the phrase to be translated says that he's not reading a book at the moment.
It's not used for immediate family, I'm learning too, however, it's because et את, is used only for direct objects.
These are things that are prefaced with "the" , i.e. , the books. Would be:
. Another direct object is names. Like : I like Idan.
אני אוהבת את עידן
אני אוהב את עידן
From the e-book, COLLOQUIAL HEBREW, pages 57-58:
THE PARTICLE ET A direct object answers the question ‘what’ or ‘whom’ in a sentence: “What are you writing? I’m writing a letter”, “Whom do you see? I see a waiter.” Direct objects are indefinite (a waiter, a letter) or definite (the waiter). In Hebrew a definite direct object must always be preceded by the particle et
I see a waiter ani ro-eh meltsar I see the waiter ani ro-eh et ha’meltsar
Since proper nouns are by nature definite, they too are preceded by : I see Avital ani ro-eh et avital The particle is never translated; it is simply a marker signalling the definite direct object.
A native speaker did expand on this if you search the discussion
Did you read the tips and notes for Duolingo Hebrew? They're not in the app. Here's the section for direct object: Duolingo אֶת The Hebrew direct object is only strictly direct when it is indefinite, as in:
take a chair - קַח כִּיסֵא take meat - קַח בָּשָׂר When definite (eg הַכִּיסֵא 'the chair'), it is generally introduced by the special preposition אֶת . This is known as the direct object marker. By definition we mean: a. a noun with הַ b. a name c. a definite pronoun
They're not options for that particular question but rather they're supposed to be options for the individual (crown) skills. Imho kind of like a beginner dictionary they give you (or are supposed to) the most common usage /for the skill you're working on. If you want tense charts or full list of definitions translated for each word, you try sites like Pealim, Reverso, etc.