Spanish language Q&A Forum

Here in Puerto Rico, it was suggested to me that one had the flavor of "perhaps" and the other "maybe", but I always forget which is which. 

Sé que la pista era para conjugar "ser", pero no entiendo porqué "éramos" es la unica que funciona aquí

Es inválido "fuimos"?

I wrote 'maestra' instead of 'profesora' and this was marked as a mistake. But why, isn't it the same?

It says in the lesson that you can use "mientras" or "mientras que" with the subjunctive to mean "as long as" or "provided that". Is there any difference between these two forms?

How to decide to use por (for because) versus porque (as in the example above):

Would it be correct to use porque in these examples?  How would one know which to use (por vs porque)?

Ha salido en la televisión por tener quince minutos de fama.
He's been on TV because he was famous for fifteen minutes.

Va a estudiar medicina por seguir la tradición familiar.
She is studying medicine because it's family tradition.

I have seen three words for car: el carro, el automóvil, y el coche. How do I know which to use? Are these regional? I see a lot about Spanish in Spain vs North America.

My understanding is that in Spanish, “un billón” represents a different quantity from “a billion”in English, and this should not be directly translated, but is rather the same as “mil millón.” 

Is my info wrong? Can there be regional variation?

HI,

In the example sentences I have now come across 'de la tarde' and 'por la tarde' both meaning 'in the afternoon'.

Are they interchangeable?

Thank you.

Regards,

Colin