Both Spanish and Portuguese belong to the same language family (Ibero-Romance languages). Therefore, they share many linguistic similarities and a similar vocabulary.
If you look closely, you will start seeing different patterns and sequences which will allow you to have access to a wide variety of words which will rapidly expand vocabulary in Portuguese.
The infographic below will provide your with 2 straightforward methods you can start applying now to boost your vocabulary in Portuguese:
1. When a word in Spanish begins with an "ll" it becomes "ch" in Portuguese
2. When a word in Spanish contains a "ie" it becomes "e" in Portuguese
These methods are very useful and extremely accurate, however, you have to be aware that it does not work 100% of the time. Have fun learning Portuguese and stay tuned in for Part 2.