Seu and sua mean your, her, and his in both portugal portuguese and brazilian portuguese. Is that correct?
The usage of perfect past tense and imperfect past tense confuses me a lot. For example,
When to use: Eu estive muito feliz
and: Eu estava muito feliz
Is the usage of these two sentences correct?
Thanks in advance
"Seu/sua" means "his/her" or "of him/her", but also can be used in Brazil as "teu" (your/yours). BUT it also can be used in Brazil as "tua" (your/yours), actually most of time. Instead of "seu/sua", to refer to the 3rd person, we use "dele/dela". Exemple:
Roubaram seu carro > Roubaram o carro dele (Someone stole his car)
Teu filho é bonito > Seu filho é bonito (Your son is beautiful)
What we call as "pretérito perfeito" is not the same than "past perfect" in English. Ok?
So, BASICALLY, you will use "pretérito perfeito" to talk about one-off situations and "pretérito imperfeito" to talk about something that you USED TO DO in the past or something you did for a while, but you don't do that anymore, like old habits. Exemple:
Ontem eu fiz comida em casa. > verbo "fazer" conjugado no pretérito perfeito
Antigamente, eu fazia comida em casa todos os dias. > verbo "fazer" conjugado no pretérito imperfeito.
About being happy... If you were a happy person, like it was part of your personality, but something very strong like a depression made you become someone else, then you actually should use the verb "SER" in "pretérito imperfeito" meaning "happy is something that I used to be, but I'm not a happy person anymore". But if you mean you were happy for a while, talking about your MOOD not your personality, and for some reason you are not FEELING happy anymore, then you say "eu estava feliz... agora não estou mais" (pretérito imperfeito). If you say "eu estive feliz" (pretérito perfeito) it means you were happy in a very specific moment, which sounds weird... You would have to explain more about it. So it's not about being wrong or not, it's about what you mean. Got it?
And remember: verbo SER is about WHO are you, verbo ESTAR is about HOW are you.
Espero ter te ajudado!