I overheard my Spanish colleague that he kept saying over the phone ¿encontraron?. I asked him what did that mean. He explained it meant "Could you find them?". I think "encontraron" is third person plural past tense so it would mean "they found ....". Could some one explain in terms of Spanish grammar as to why or how ¿encontraron? could mean ""Could you find them?". Thanks
It is 3rd person plural preterite (ellos/ellas). It's also 2nd person plural preterite (ustedes). It could mean, "Did they find?". It could also mean, "Did you (all/guys) find?". It depends on the context, which I assume the person on the other end of the phone knew.
In my experience with Spanish you don't really have the same structure as you do in English, "Did you...?" The question is implied by your tone. "¿Me pasas la leche, por favor?" literally means "You pass me the milk, please?" but the tone in which you use it turns the statement into a question.