The tips section for this lesson gives the spelling of the word for "adjective" as "επίδετο". Is this an alternative spelling or a typo? Thanks!
On the first screen of each skills page, when you've chosen a skill but before you actually start doing the individual lessons on it.
Only visible on the website (and if you have a large enough screen).
Not included in the mobile apps, nor (apparently) when the website is viewed on a smartphone browser with a screen that's "too small" -- one reason why I consider the apps to be unsuitable for learning a language on Duolingo as all the lesson notes and grammar explanations are hidden from you, though they may be useful for practising a lesson you have learned through the website.
These links will not only show you how to get the Greek keyboard but also how to find the Greek letters on it, how to add accents etc.
https://www.duolingo.com/comment/22040507 It will also help you learn the alphabet and where to find other useful links. And here is another to help you navigate Duolingo
FAQ - General Questions, Bugs & Reports https://www.duolingo.com/comment/23799672
Some simple rules to get you started:
Always read the comments before posting.
Read the Tips & notes right below the list of lessons on your Homepage Read the drop down hints. Pass your cursor over a word and a list of words will appear. https://www.duolingo.com/guidelines https://www.duolingo.com/comment/8000024
If you have questions just ask.
That would have to be "ένα επίθετο". If you are referring to the hint "an adjective" that might be used in a sentence where the English required an article. Not all hints are viable for each exercise as in a dictionary you might find a variety of definitions for a word but not all will be correct for what you want to express.
With the Duo hints it's safest to choose the first word. That's usually the one needed for the sentence it's under.