It's not even really about learning Greek or Latin as a true spoken language. It's about known the roots of the linguistics for understanding why a word is even created in the first place.

English is a really messy language but there are many simple underlying roots that can tell you what the word means with context clues after hearing it for the first time.

Also learning the International Phonetic Alphabet is probably another huge boon for comprehension, the nicer books often include IPA spelling for crazy off the rip words