Making connections in Greek

Today we were listening to this week's new vocabulary words, and the first one was biblion, meaning book. Mary said, "Hey, that sounds like the Spanish word for library!" It's neat to see her make connections like that. And it's amazing how many words that came into English (or Spanish, obviously) from Latin, came into Latin from Greek. Studying Greek instead of Latin makes me feel like we're looking back further into the history of language. I'm still convinced our word dowry is related to the Greek word doron (gift) from last week's vocabulary. I can't find a direct link in any online etymology site I've visited, but it seems they both come from the same Indo European root.