Ah, yes, Greek spelling... You are only in the beginning, so don't worry, gradually spelling will start to make some sense. :)
To help you with this word and give you an idea of what patterns to look for in Greek spelling, here is why ξυλόφωνο is spelt as it is:
- it is a compound word, its parts being ξύλο and φωνή.
- ξύλο means wood, it is always spelt with an υ, which is an 'ee' sound when on its own. Other words like this are ξυλοκόπος (woodcutter/lumberjack) and ξυλώδης (woody). ξύλο is a neuter word so its 'o' ending is ο, not ω.
- φωνή means voice, its 'o' sound is always spelt with an ω, e.g. φωνάζω = I yell, τηλέφωνο = telephone, φώνημα = phoneme etc. φωνή is a feminine noun so its 'ee' ending is η.
- the compound word ξυλόφωνο is neuter, so its 'o' ending is ο.
HOW TO GET THE GREEK KEYBOARD 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.
For a cell phone http://www.wikihow.com/Change-the-Language-on-a-Cell-Phone
How to add the accent. On a mobile just hold the letter for an extra second or two and there will appear a variety of that letter with accents. Slide up to the one you want.
THE GREEK ALPHABET https://www.duolingo.com/comment/22424028
https://www.duolingo.com/comment/22040507 It will also help you learn the alphabet and where to find other
FAQ - General Questions, Bugs & Reports https://www.duolingo.com/comment/23799672
Some simple hints to get you started:
Always read the comments before posting.
Read the Tips & notes, on the first page of each lesson you’ll see an image of a light bulb. Click on that.
Read the drop down hints. Pass your cursor over a word and a list of words will appear. The top word/phrase is usually the best choice.
These are the official Duolingo guidelines which you should read. https://www.duolingo.com/guidelines And these will answer lots of questions about how Duo works. https://www.duolingo.com/comment/8000024
If you have questions just ask.