what makes a text hard/easy

[daivid]

Things that make a Greek text hard: low frequency words, rare forms of word both in the sense of less used tenses and in the sense of examples of more common cases/tenses that are highly irregular, long sentences, low frequency verbal forms, idioms.
However long sentences can be quite easy if the syntax is simple. A long description can be quite easy if is a mere list. Also high frequency words that have multiple meanings can be very difficult unless the sentence is in other ways simple so as to provide the kind of context that will allow the reader to single out which of the meanings is intended.
Repetition of words, forms and syntax in a text makes it much easier as even if a reader has trouble the first time they are much less likely to have trouble subsequent times.

I suspect that the above will be on most peoples lists. I do think that is hard to pick out which is important. All of the above make their contributions. For me at least, the extra difficulty is not linear. By that I mean, every extra difficulty adds an ever greater level of difficulty. Hence a sentence with two unknown words is not twice as difficult but more like four times as difficult.