io sto mangiando - eu estou comendo

io sto leggendo - eu estou lendo

lei stava facendo - ela estava fazendo

I was learning Italian some years ago in a class where others students were all English speakers, and it felt like cheating as the grammar was basically the same, just the words changed a bit, so I was having a much better time than anyone else! But when the teacher spoke fluently to me in Italian, obviously I would suddenly realize my Italian was still very poor and I had a lot to learn.

EDIT: by the way, the author must have meant that other germanic languages don't have "gerundio"? Looks like all Latin languages do.