Yep, this is one DL's standard totally cr@p and meaningless, in English at least, sentences.
Sorry,but "I announce my book" does not make sense in English.! I
m a British English teacher and have worked for years in Copenhagen. I am really enjoying Duolingo, but some of the translations into English are awkward or wrong.. We call this Denglish ! Dont you have a native speaker to help or advise you? The whole idea of Duolingo is excellent and the design of the course is very good. It`s a shame that many of these translations into English let it down. I mean this as constructive criticism and not to be nasty.
Three things here:
I do think that "I announce my book" (or the progressive "I am announcing my book") is a perfectly valid sentence. My new book, "Bricks in the Sun", is coming out next month. There, I announced it.
Despite being an English teacher, you don't seem to have a lot of regard for proper punctuation. Granted, if you're on phone, mistakes like a missing space after a comma and such are understandable, but using backticks ` for apostrophes ' is going to lead to a weird formatting on a Markdown-based site. Especially on phone actual apostrophes should be accessible more easily than rogue diacritical symbols.
Criticism does not become constructive just because you say so. Constructive criticism is made up of two essential parts: analysing the problem, and giving suggestions to fix the problem or improve the situation. Your text is lacking the latter part, with the only glint of a suggestion being your question about native English speakers. You could have suggested a different translation, for example, like "I advertise my book" which is also in the range of at annoncere. Or just say how you'd express the announcement of a book differently.
en annonce is only the kind of advertisement that is printed in a magazine/newspaper (or "printed" online). Generally, advertisement is called reklame.
Yes, "I'm going to announce my next book tonight" makes more sense, but that is not what the statement is in this particular translation.
"I announce my book" is meaningless as you generally don't announce the book itself. You announce the release date, or the title, etc. . . You could even announce that a book is forthcoming. "I am proud to announce the release of the anticipated sequel to "Poor Sentence Structure," Winter 2018." "I am excited to announce the title of my new book: "Weird Stuff Duolingo Drops in Translation" . .