I personally did not find his accent an issue, however he is still one of the worst professors I have ever had. He stood in front of the class the entire time, barely making eye contact and never engaged us. All he did was write every single word he said on the chalk board. He also focused most of the lecture on proofs and theorems and disregarded the actual calculations and didn't give many examples, which made it hard to fully understand the material. One time I went to him for help and it was clear he did not want to help me, and he was very rude and condescending. I definitely recommend choosing a different professor.

It's true that Professor Pereira has a strong accent. However, it should not be a reason for Professor Pereira not being a good teacher. The first day I went to his class, I thought I might screw up this class because I basically couldn't understand what he was talking. However, if you pay enough attention during the class, you will find out that he is a really good teacher. He might know he has a strong accent. So what he wrote down were the main point. It's ok if you don't understand his spoken English!
He always welcomed questions though most of the time he couldn't understand the questions when students spoke too fast. But once he understood, he would try his best to answer them and made sure he gave the answers students wanted.
One of the best thing of the class was that the grade came out very fast. We had two midterms and one final this semester. All of the grades came out at the same day we took exams. That's really helpful because we would have enough time to go to his office hour and check the exams.

Cannot speak English and thus doesn't explain anything.