The Italian translation would be "I am finishing to read the book." in English. But the English sentence has two consecutive gerunds. Can one say "Sto finendo leggendo il libro."?
To finish doing is finire di fare. I don't think the number of gerunds matters.
Thanks, that's useful. But can one say "Sto finendo leggendo il libro" or not?
I think two Italian gerunds like that would be ungrammatical, but maybe someone else has a better idea.
But I question the assumption that the English has two successive gerunds. Finishing here seems to be a present participle.