Portuguese Word Frequency - Top 5000 Words

A legitimate tool to focus on pure vocabulary retention is to use word frequency lists.  

Here's is a .pdf copy to check out I found online.  

http://jons2580.free.fr/75%20livres%20d%27enseignement%20de%20langues/Frequency%20dictionary%20portuguese.pdf

I use this list to help build memory palaces for new words.  If the phrase "memory palace" is a new phrase, I would recommend this book.  Its an easy read (or Audible listen), and I found it interesting (both the practical application of the techniques discussed for language acquisition, but the historical examples the author uses to support the validity of the techniques discussed). 

http://www.amazon.com/Moonwalking-Einstein-Science-Remembering-Everything/dp/0143120530