Pop-Up Box Explanations repository
It would be useful to have a repository that could be accessed, perhaps on the vocabulary page, for all the "explanation pop-up box" contents. These items are very useful but once you move on to the next page in the lesson, you have no way of retrieving the information if you need it again later. Also such a place would give you an opportunity to learn many of these grammatical items in advance so that the sentences in the lessons might make more sense to you the first time around. A list of common idioms would also be useful.
This is an excellent idea. I did run across a discussion post the other day saying students are welcome to use dictionaries, grammar books, and whatever other materials they have available, but it would still be helpful to have material tailored to Duolingo. This is especially important in cases where grammar points get introduced in English first. For example, there was a sentence starting with "one of" to translate into French. I started with "un" but the correct translation is "l'un". I don't recall seeing that in French first.Translating from English to the foreign language is a lot harder (15 to 20 times harder, according to one estimate) than the other way.around. I could avoid a lot of errors if I could read something that would give me a clue when such sentences turn up.