Type what you hear exercise: I wrote Το τρένο... and was told that I used the wrong word. I don't know if you can change it to accept both variants (I assume Type what you hear allows for only one possible correct answer).
If the same Greek spelling was consistently used for all the main answers in this course (the other being optional) then one could just remember which one is required, but since various people have contributed to the course sometimes τρένο is the prefered variant, sometimes τραίνο. As for me, I actually do prefer the older spelling τραίνο (since it retains the origin/etymology of the word), but the 'official' variant (taught in the schools) is the simplified τρένο (see ΛΚΝ etc).
Yes, there are both correct, but as soon as we accept the modern way, in orthography, τρένο considered "more correct". The children in Greece learn writing this way, some older than this age ;) like me use to write τραίνο. It is a foreign word imported, i think from French, as English were not so widely spoken as a second language in the 19th c., even this word is common. The Greek word is σιδηρόδρομος=σίδηρος + δρόμος as you maybe know, a greek translation from the French words "chemin de fer".
It is so difficult to find the origin of loan words sometimes. My speculation was explained above. I really don't know. The Italian loan words have most likely the itinerary from the Ionian Islands which were under the Venetian rule and many words imported from them. This very word, τρένο than was written many years as τραίνο comes from scholars or journalists who had used this word as it was written from their resources. Since most of them were French-speaking that time, the 19th c., I suppose that it came from French. I cannot prove it of course, unless I find the first publication in Greek about train. :)
At least according to Μπαμπινιώτης this word has a French origin (from where its roots can be traced further back to Latin of course). In his Ετυμολογικό Λεξικό της Νέας Ελληνικής Γλώσσας he states*:
τρένο ΕΤΥΜ. \< ιταλ. treno \< γαλλ. train \< ρ. traîner «τραυώ, σύρω, κουβαλώ», για το οποίο βλ.λ. τρενάρω.
After an explanation of the semantical evolution this word went through in French until it acquired the meaning we are discussing here, he also adds a short article on the correct spelling:
ΟΡΘΟΓΡΑΦΙΑ τρένο ή τραίνο;
Επειδή προέρχεται από το γαλλ. train και εξαιτίας της παρουσίας και επίδρασης τού αγγλ. train, η λέξη γραφόταν στο παρελθόν συνήθως με -αί-: τραίνο. Εντούτοις, ως ξένη λέξη τής Ελληνικής απλογραφείται τρένο (με -έ-).
Unfortunately, Μπαμπινιώτης does not explain how the spoken word itself entered Greek from French by way of Italian whereas its original Greek spelling was imported directly from French, but Stergi3's explanation seems to be the most likely.
[*quoting from the Second Edition of 2011]
No, I don't think that the way to come to Greek is the above proposed. A rule of thumb in Modern Greek is to use phonetic orthography for foreign words, a trend that came to Greek just some decades ago. When I was a student we were taught to write it as τραίνο, and many dictionaries keep this way, still today. The word τρένο comes from French, I can accept it and then this writing transformed to τρένο, as many foreign words did, considering ε more simplified than αι.
"οι ξενικές λέξεις μεταγράφονται φωνητικά καθώς και οι μεταχριστιανικές γενικά λέξεις και καταλήξεις ξένης καταγωγής, που γράφονται με απλά φωνήεντα και με απλά σύμφωνα».
The above text comes from the Modern Greek Grammar by Manolis Triantafyllidis (1941), a classical Grammar book.
Why were we taught writing τραίνο instead of τρένο. Well, this is a consequence of the influence of Katharevousa, I cannot understand why Babiniotis proposed Italian influence, in a word that concerns an invention of the 19th c., maybe he knows something more. Or maybe both are correct. That is the word came from French and then simplified and in the same time introduced from Italy to the Ionian islands. But I don't know such a way.
Notice that similar words or names is more preferable to write them with ε, i.e. Voltaire=Βολτέρος, not Βολταίρος.
Notice that my Google Thesaurus consider both writings correct
I haven't been able to follow all the discussions on the Greek forum for quite some time, but if nothing has changed the following still holds true for
Type what you hear exercises (but not for translation exercises):
The duolingo algorithm cannot detect variant spellings of the same word or homophones as correct. The only accepted answer is the original sentence (i.e. the one at the top of this thread, in this case with τραίνο). The only possible solution is to remember the expected spelling.
If it's marked wrong you should h ave made a Report.
TIPS TO HELP YOU LEARN + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links. https://forum.duolingo.com/topic/936
However, if it was a Listening Exercise only "τραίνο" would be accepted.