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

Yes

The word "aumentar" is identical in meaning, spelling, and grammatical function in both Brazilian and Continental Portuguese. The only difference lies in pronunciation:

• Brazilian Portuguese: The pronunciation is more "open." Vowels are clearly articulated, and the rhythm is more melodic and syllable-timed.
• Continental Portuguese: The pronunciation is more "closed." Unstressed vowels are often reduced or almost silenced (a phenomenon called vowel reduction), making the language sound more consonant-heavy and stress-timed.

Brazilian Portuguese Examples

1. "Pode aumentar o volume da TV?" (Can you turn up the TV volume?)
2. "O preço da gasolina aumentou muito." (The price of gasoline increased a lot.)
3. "Eles vão aumentar o meu salário no mês que vem." (They are going to increase my salary next month.)
4. "A empresa quer aumentar a equipe." (The company wants to increase the team.)
5. "A chuva está aumentando cada vez mais." (The rain is increasing more and more.)

Continental Portuguese Examples

1. "Podes aumentar o som?" (Can you turn up the sound?)
2. "O preço da gasolina subiu muito." (The price of gasoline went up a lot.)
3. "Vão aumentar-me o salário no próximo mês." (They are going to increase my salary next month.)
4. "A empresa quer aumentar a equipa." (The company wants to increase the team.)
5. "A chuva está a aumentar cada vez mais." (The rain is increasing more and more.)