I would like to know how to use past tenses with verbs like 'ser', 'estar', 'tener' 'vivir'. Specifically, I can say 'Pensaba en ti' and 'Pense en ti'. They're equivalent of english 'I was thinking about you' and 'I thought about you'. The problem is, they mean the same (I think), so I am never sure which form is better.
I can say 'Estaba en Espana' and 'Estuve en Espana' what again mean the same. Which form should I use?
I can say 'Tenia un perro' and 'Tuve un perro'. Both mean I don't own the dog now.
Look at the verb 'cocinar'. If I say 'Cocinaba una sopa' and 'Cocine una sopa' they don't mean the same. The second tense means the action is done, but first informs us that the subject started some action, but we don't know whether he had done this.
But with 'specifically' verbs there's no divison like above in logical context.
I hope you understand my problem and will explain me this, especially in my native language verbs like tener, estar, etc. don't have indefinido(past simple tense), only imperfecto(past continous), so it may be the reason of my question.