George is doing his homework today. He needs to memorize 30 French words.
Is the verb "memorize" used correctly in the following two sentences?
George has memorized 30 French words for an hour.
George has been memorizing 30 French words for an hour.
In my opinion, George has memorized indicates a completion. So it doesn't go with "for an hour".
On the other hand, George has been memorizing indicates an ongoing activity. It can go with a duration and fits the context, but it doesn't go well with "30 French words". We don't say George has been reading five books for a month, for example. It sounds like George was reading the five books simultaneously. Rather, we'd delete the words "five".