I think the first is the correct way to say, tell me something....can the second way also be used? Gracias.
Dime una cosa VS dime algo
Dime una cosita.....which often triggers: con qué letrita...
Well, this is what we use when talking in general...
dime algo de tu primo, algo de tu trabajo
Dime una cosa...a qué hora llegas mañana?
I would not even translate cosa here: Tell me....at what time do you....
I agree with Heidita. I use both, although I give preference to: "Dime una cosa".
Thinking about it quickly, it seems like I prefer to use "Dime una cosa" if I'm approaching someone out of the blue, wanting a quick answer to something that is on my mind.
"Oye, dime una cosa, es cierto que...?"
"Dime algo" may come up during the flow of a conversation, if I suddenly think of something that needs clarification, for example.
"Aja, ya veo - eso es muy interesante. Ahora, dime algo, ¿cómo es que comenzaste a trabajar en..."
I think they both sound correct, but I would use the second one.
Truly? I really think the first is the correct one. Your profile leaves much to be desired April, so I can't grasp what your level is, and in truth, nor can I tell you what mine is, though my profile says intermediate. Gracias! de antemano? no, con gracias anticipadas!