Ser ever switched to Estar?

Ser ever switched to Estar?
 

Okay, I understand about ser and estar and the different uses for them. What I'm wondering is, how strict are those uses? For example, if someone was working a job as a secretary, but they knew from the beginning that the job was temporary, could they say "Estoy un secretario.", just to emphasize the fact? Or would that just be wrong? Or, another example, say someone was being mean and instead of saying, "Eres mi capitán," they said, "Estás mi capitán." Would that be at all correct, or am I thinking too hard? :)

Both sound incorrect to me. Personal/definitive characteristics and professions are always expressed using ser, even if they may change.

If you want to use "estar" to emphasize this temporary situation, you can say "Estoy de secretario/secretaria".
The preposition determines the condition of the speaker.


I cannot think about a situation in which "estás" could replace "eres", so it sounds just wrong to me... however I think I'm not getting exactly what you mean. What is your idea in English:?:

Which would then mean something like:

I'm here as a secretary.
I'm being a secretary (now).

Okay, I see. Thank you!

The second one, as if someone were saying, "You're the captain now, but not for long."

Hmm... my first choice wouldn't be "ser" or "estar", but rather something like "tú mandas, pero no por mucho tiempo".
*"Mandar" = "to command, to give orders".

If you would like to keep the word "captain" (which would make a nice rhetorical figure), you could say "estás de capitán, pero no por mucho tiempo" ("you're the captain now, but not for long")... just make sure that the context is clear. :)

Yes, you can use "estar" implying a short time, but also "ser" with time notes.
"hoy estás de capitán" /"por ahora estás de capitán"/"Hoy serás capitán"/"Por ahora serás el capitán" All means a temporary status.

"Hoy soy el secretario"/"Hoy estoy de secretario" are also good.

Saludos :D