Without an example, it is really hard to translate this. Sure can be so many things: Can you go? - "Sure!" Meaning that you can definitely go. It's a commitment. (por supuesto) Is grass green? - "Sure it is." Meaning that it definitely is green. (claro) I promise you, I didn't sleep with James! - "Sure you didn't." This is sarcasm, meaning that you don't actually believe what the person said. The word sure is often used for sarcasm and agreeing with something verbally that you don't agree with mentally. (No sé cómo se dice en español) Those are just some examples. In general, a final conversational "sure" can be translated as por supuesto or claro. Here is a fantastic website for other definitions and uses of the word "sure": http://www.wordreference.com/es/translation.asp?tranword=sure Hope that helps.