"Ahora estoy leyendo un libro."
Translation:I am reading a book now.
even though in english the "now" in this sentence can be in four different places, I have noticed in spanish, and especially on dl, it should be first or last with this type of sentence. Yes, your answer should be accepted, but if you want to play it safe, go with the literal "now I am reading a book", or the optional "I am reading a book now"
I answered it correctly. The words were in a different order, but, they were correct.
Yes, a gerund is a verb form used as a noun. These examples are either errors or I'm missing something.
I think that "Right now, I am reading a book" is an acceptable and accurate translation of this sentence. It communicates the immediacy/ongoing nature of the verb form more clearly than "I am reading a book now"--which, because of how odd English is, is actually a somewhat ambiguous statement compared to the first.
Attention everyone! I am reading a book now! Do not disturb! Further bulletins as events warrant!