segura and cierto - subtle differences?

Question

This was a sentence I wrote and corrected for Palabra del Día. I was corrected from "Estoy cierto' to "estoy segura de". My question: Is there a subtle difference between the use of cierto and segura that someone can explain to me or give me a link? In English I can use these 2 interchangeably in this sentence so it's hard for me to understand.

No estoy segura de dónde está él, pero pienso que está atrás.

Great question, Katy. - --Mariana--, Mar 22, 2012

Indeed good question! Mariana and comunacho are right. Eye-opener ;-) - mcl020, Mar 22, 2012

Thank you and as always, I'm getting good feedback. - katydew, Mar 23, 2012

Answer 1

"Estoy cierto de que temblará hoy" it's the same as saying "Im absolutly certain that today will be an earthquake". It's stronger that "estoy seguro de que". But this form is not very extended. In Spain isn't used, neither here in Chile. You better use "seguro"; that's accepted everywhere as correct.

Thank you very much. - katydew, Mar 22, 2012

Answer 2

From what I know seguro means safe as in: not dangerous, beneficial, no need to worry, you can rest assured, feel sure, .....
Hay que tener un securo (médico).
Este camino es seguro.

The other cierto means : be sure of, know for sure:
Él no está cierto de dónde está katy.

[But cierto can also mean: certain, a peculiar kind of, ...
Hay ciertas películas que no deberías ver.]

to me its the same either way, e.g.; I'm not sure where he is, but I think he is behind. - ChaseBaromeo, Mar 22, 2012

Very helpful. Thans MC. - katydew, Mar 22, 2012

On a side note, how did you make the capital E with an accent on it. Mine won't do that. - katydew, Mar 23, 2012

Answer 3

My experience is:

¿Quieres comer aquí en McDonalds...estás segura? Sí, estoy segura = Yes, I'm sure.

¿Estás cierto que Julio está casado? Bueno, no, no estoy cierto = No, I'm not certain of that.

Ehh, Marianne, weren't you interested in Julio-junior? ;-)))))))) - mcl020, Mar 22, 2012

That's helpful. - katydew, Mar 22, 2012