"Public transport helps the city."
Translation:Τα μέσα μαζικής μεταφοράς βοηθούν την πόλη.
Correct. No need for the plural δημόσιες συγκοινωνίες, since we are talking about a single city. I'll correct it, thanks for your input. ^.^
Thank you, I cannot remember ever seeing it in English in the plural even if you are talking about multiple cities. In those circumstances you might say something like "the various means of public transport in different cities" or " the public transport systems etc".
Yeah, I agree. You could use the plural means of public transport = μέσα μαζικής μεταφοράς in a single city (meaning more than one, like buses,metro,etc), but I think "δημόσια συγκοινωνία" is not suppposed to have a plural xP