This is a hard question. In this case we use those two verbes equally, but there a reason and it depends on what do you really want to express: When we say ES CORRECTO we refer the phrase itself, the phrase is correct, because it is always correct like that (at least that grammar change). SER express permanence. When we said ESTÁ CORRECTA we refer the way we write (the action of writing), "the phrase is write correctly", although, speacially in speaking, we replace "the phrase" and we just say/write "It is correct/ is correct" (the phrase or whatever "that" is). Because the form to write the phrase can change we used ESTAR, expressing impermanence. Hope that can help you a little.

También depende del tiempo de conjugación de tu frase. Por ejemplo, algunas veces usas un verbo en copretérito después del pronombre relativo "que": "Consideraba que estaba bien" o "Consideré que estaba bien".

Jorge's answer is correct, but in México and in Latin America we omit almost always the personal pronoun (I don't know if in Spain they do the same), so in that case it would be "experimentaré..." (and it's still very polite), but most common is "Voy a experimentar" o "yo voy a experimentar". Cheers

Hi. I'm mexican. It is really difficult to define the mexican culture, because there are a lot of differents cultures in this country. I could say that even myself don't know everything (living almost my entire life in México). But maybe yes, you can find some shared (positive) qualities like kindness, happiness (even in the worst moments most of mexican people knows how to laugh about) and, yes, most of us like to celebrate, no matter what. As always, and like all countries, we cannot generalize, but I think those qualities you can find them almost everywhere. If you have another question, just ask :)

Concuerdo con Victor. En México se usa "pasta de dientes". Creo que es en España que dicen "dentrífico". Saludos.