Gracias, Vicentin! Very helpful!

First, "Algo" = " Something", so, it can be male or female but singular. "Tengo algo en mi zapato" ( Something is in my shoe) "Quiero algo frio" ( I want something cold) "Algo me obstruye el camino" (Something blocks the road) Alguien.(somebody) This is used to point out a person. * Alguien me robó mi calculadora. *¿Es de alguien este libro? Alguna. To point out something or someone but only in Spanish must says like this. For exemple. *In English you say. Any idea?. In spanish you must say. ¿Alguna idea? because "idea" is a female word in spanish. If you refers to talk about a male word like "Argument" in english you say. *Any argumen to discuss?, but in spanish you must say. " ¿Algún argumento para debatir( discutir)? A Game of Words.. You use "Alguno" when you want to talk about one thing, place or person.(male word) * ¿Alguno de ustedes va a ir a México este año? (Anybody is going to visit Mexico this Year?) You use "Alguna" when you want to talk about one thing,place or person.(feamale word) *Si esta no es mi mochila, alguna de aquellas debe de serlo. (If any of this bags are mine, some one else must be!) If you already understand the meaning of this, you're in the other side. Then, when you are talking about the plural of "alguno", you say "algunos". and If you talk about the plural od "alguna" you say "algunas". *Algunas manzanas están podridas. *Algunos perros son bonitos. *Alguno de ustedes debe de tener frío. *Si alguna de ustedes está enferma, dígalo ahora!. if you have some doubts, please write another question.