En algunos países dicen "papas" y en otros se dicen "patatas" Quiero papas/patatas.

Hola! Well, if you wanted to say "I want some potatoes." I would say it like this: "Quiero un poco de papas." or, like Sai suggested, just say "Quiero papas." ( if you don't mind not emphasizing the "some" too much ) Now if you wanted to say "I want some fries." I would say it like this: "Quiero un poco de papas fritas." or "Quiero papas fritas." The word "algunos" does exist, but if you wanted to use this word with potatoes, you must say: "algunas papas", and not "algunos", because "papas" is a feminine word. And, you can use the phrase "algunas papas" but in other contexts, for example, you could say: "Voy a tomar algunas papas del canasto." ( I'm going to take some potatoes from the basket. ) So, summing up, when you want some (referring to food), you don't use "algunos" or "algunas" too often, even though it's grammatically correct, and people will understand you, what I mean is that it's not forbidden or even incorrect, I'm just saying we tend to use more "un poco de" or just the name of the food, rather than "algunos" or "algunas". But, when you want to emphasize that some elements of a group share certain characteristics, you can use "algunos" or "algunas" as the example with the potatoes in the basket showed.

Gracias

En español solo tienes que decir {Quiero papas.