Is the word frequentes the same in Brazilian and European Portuguese?

Yes

The only differences between the use of "frequentes" in Brazilian Portuguese and Continental Portuguese are in pronunciation. The spelling, grammar, and meaning (referring to something that happens often) remain identical.

In terms of pronunciation:

• Vowels: In Brazilian Portuguese, the unstressed "e" in the final syllable of "frequentes" is typically more audible and pronounced (often sounding like a soft "i"). In Continental Portuguese, this vowel is highly reduced and almost silent.
• Sibilance: In most regions of Brazil, the "s" at the end of the word is pronounced as a sharp [s]. In Portugal, the "s" is almost always pronounced as [ʃ], which sounds like the "sh" in "shoe."

Brazilian Portuguese Examples

1. As chuvas frequentes causam alagamentos. (Frequent rains cause flooding.)
2. Ela faz exercícios frequentes na academia. (She does frequent exercises at the gym.)
3. Existem erros frequentes neste programa. (There are frequent errors in this program.)
4. Ele faz visitas frequentes ao médico. (He makes frequent visits to the doctor.)
5. São problemas frequentes por aqui. (They are frequent problems around here.)

Continental Portuguese Examples

1. As chuvas frequentes causam inundações. (Frequent rains cause flooding.)
2. Ela faz exercícios frequentes no ginásio. (She does frequent exercises at the gym.)
3. Verificam-se erros frequentes neste programa. (Frequent errors are found in this program.)
4. Ele faz visitas frequentes ao médico. (He makes frequent visits to the doctor.)
5. São problemas frequentes por cá. (They are frequent problems around here.)