Language Patterns: Spanish and Portuguese
Noticing patterns from Spanish -> Portuguese helped me improve really quickly, because I would be able to guess a word in Portuguese based on the patterns I knew and the word I knew in Spanish.
All words that are similar (no matter what language) may be an exception though, so it’s not always 100% reliable.
This also helps with trying to figure out pronunciation. The first one that comes to mind is the ñ/nh example. They sound similar except one is with a different accent.
*Note: In the –les/–is chart, there’s the word, “legais” under Portuguese. It means “legal” but is used frequently as “cool” in Brazil.
Example: Você é muito legal (singular), Vocês são muito legais (plural)