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

Yes

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

In Brazilian Portuguese, vowels are generally more open and clearly articulated. The unstressed vowels in "começaram" (specifically the 'e' and the final 'a') are pronounced with more clarity. In Continental Portuguese, unstressed vowels tend to be "reduced" or "closed." This means a Portuguese person might pronounce the word with a much shorter, more muffled, or almost neutralized sound in the unstressed syllables, making the word sound more compressed than it does in Brazil.

Brazilian Portuguese Examples

1. Eles começaram a estudar ontem. (They started studying yesterday.)
2. As aulas começaram muito tarde hoje. (Classes started very late today.)
3. Meus amigos começaram a viajar pelo mundo. (My friends started traveling the world.)
4. As crianças começaram a brincar no parque. (The children started playing in the park.)
5. Os filmes começaram agora pouco. (The movies started a little while ago.)

Continental Portuguese Examples

1. Eles começaram a estudar ontem. (They started studying yesterday.)
2. As aulas começaram com um atraso enorme. (Classes started with a huge delay.)
3. Os meus amigos começaram a viajar pelo mundo. (My friends started traveling the world.)
4. As crianças começaram a brincar no parque. (The children started playing in the park.)
5. Os filmes começaram agora mesmo. (The movies started just now.)