How does one know that 'Elles' and the conjugation of 'write' are plural based on pronunciation?
you should hear the final "v" sound at the end of the verb. singular is "elle nous écrit un livre" (no V)
Please consider the analysis of this sentence: Where is the verb? "écrivent", from verb "écrire", conjugated at the 3rd person plural, present tense. Who is writing? "elles", feminine plural pronoun and subject of the verb What is written? "un livre", direct object of the verb To whom the book is written to? "nous", indirect object of the verb.
In this case, the indirect object is placed before the verb. In English, you could have an alternative construction to mean the same thing: "they write a book to us" but in French "elles écrivent un livre à nous" would not be correct.
It wouldn't be correct in English either! We might say "they are writing a book FOR us or ABOUT us or a book dedicated TO us, or they are writing us a book - the "for" omitted- but "they write a book to us" ---- is not an English construction.
I had the "select the words" variant of this question. I chose "Elles on écrivent un livre" and was marked wrong. Why can't I use "on" instead of "nous" here or is Duolingo missing that possibility?
"on" is defective, which means that it cannot have any function in a sentence as "we" does.
in particular, "on" cannot be an object (direct or indirect with a preposition).
Do you mean "on" can't be used for "us", only "we"?
The website and the iOS app have had a male voice as well as the female voice for a while. The Android app still only has the female voice.
Now the Android one also has the male voices in different languages. It, however, wonders me why they don't put so many other features that say their website has on their android app.
Really? I use the Android app every day for French, it's always updated to the most recent version and I've never heard a male voice on it.
My last update was 2 weeks ago (13 May 2016) and I heard a male voice on it for the first time today! 28 May 2016. It's a bit odd that different users are getting it at different times.
Plural forms Indistinguishable from singular unless we can hear a third syllable in écrivent!!!
Wow, this one got me too: I could not hear the plural in the spoken sentence.