How do you use Alguno and its other forms correctly?

Question

NOTE: When I refer to Alguno I'm referring to all of its forms.

The Pronoun Alguno means - one, some, someone(or similar meanings)

And

The Adjective Alguno means - a, some(or similar meanings)

1. This was taken from the question Algún to represent an indefinite quantity?

While alguno/Alguna are used for singular names and algunos/algunas for plural names you can use "alguno/alguna" for plural if you use the preposition "de"

Alguno de mis amigos no fue a la fiesta. Some of my friends were not at the party.

Alguno amigos no fueron a la fiesta. Some friends were not at the party.

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Just to clarify,

Algunos de mis amigos no fue a la fiesta. Some of my friends were not at the party.

is this also correct?

secondly, in the second sentence "Alguno amigos" -the singular form is used with amigos - was used even though the preposition de was not used. I am confused as to why alguno stays in the singular form in this case.

2.

algún idiota dejó la puerta abierta some fool left the door open

in this sentence "some fool" places no emphasis on gender so why was algún used and how does one decide in such a case?

3.

some of / one of

Algunos de mis amigos son médicos - Some of my friends are doctors.

¿Conoces a alguna de las niñas? - Do you know some of the girls?

Alguno de ustedes tiene que acompañarme.One of you has to come with me.

why is this use of alguno classified as a pronoun rather than an adjective?

I ate some of the apples(to me "some of" acts as a quantitative adjective)

vs

 I ate some apples (to me "some" acts as a pronoun)

4.

one vs some

Voy a salir con algunas de las chicas. I'm going out with one of the girls.

Voy a estudiar con algunas de las madres. I'm going to study with some of the mothers.)

¿Quieres alguno más? Do you want one more?

¿Quieres alguno más? Do you want some more?

how do i correctly use alguno to mean one or some?

5.

Alguno to me a

¿conoces algún hotel barato? do you know a cheap hotel?

¿Compraste alguna blusa en la tienda? Did you buy a blouse in the store?

¿Tienes alguna camiseta que me puedes prestar?Do you have a shirt that you can lend me?

¿Tienes alguna mascota en tu casa? Do you have a pet?

Tenemos algunas bolsas, pero vamos a necesitar más.We have a few bags, but we'll be needing more.

The fact that alguno can mean a is very confusing to me. how do you know if the intended meaning is a, one or some?

6.

The pronoun Alguno vs alguien

Alguno tiene que ayudarme con mi tarea de matemáticas.Someone has to help me with my math homework.

¿Me puede ayudar alguno a cambiar una llanta pinchada?Can someone help me change a flat tire?

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Necesito a alguien que pueda hablar inglés. I need someone who can speak English.

Alguien dejó estas flores sobre mi escritorio. Someone left these flowers on my desk

¿Hay alguien en la casa?Is there someone in the house?

¿Está alguien en peligro?Is someone in danger?

Are there any differences between Alguno and alguien or can they be used interchangeably when the meaning is someone?

Answer 1

1.

Your original intuition (in the linked question) is almost right, there is only a nuance you may have been missing.

Algún/alguno/alguna are singular, while algunos/algunas are plural. They all have to match in number with the words being modified.

The nuance is that the singular can mean a restricted number. You use singular to mean one, but the root adds the sense of 'approximately'. Hence when you say algún you could translate it as either some or (arguably better) a few, or, freely but more expressively: one or two (or maybe three?).

Regarding your examples:

Alguno de mis amigos no fue a la fiesta

A few of my friends weren't at the party

Alguno amigos [...]

This is wrong: alguno and amigos must match in number: either algún amigo [mío] or algunos amigos [míos]. You get the freedom to use the singular in the first case for the same reason why in English you can say one of my friends was [somewhere] and many of my friends were [somewhere]: De mis amigos is only a modifier and does not need to match in number.

Algunos de mis amigos no fue a la fiesta

This is also wrong: the subject is algunos and must match the verb fue: algunos de mis amigos no fueron a la fiesta

2.

In Spanish the masculine gender doubles as neuter son when you don't want/need to specify you just go with it. This is especially common in plurals: anyone can say nosotros to mean a group of mixed gender. In this case,

• If you said alguna idiota you are saying you know it was a woman
• If it is ambiguous and you want to make explicit that the fool was male, you have to add a word, e.g. algún hombre idiota, but this is rarely needed

3.

Alguno as a pronoun in this case because adjectives can't be subject or object of the sentence without becoming pronouns (de ustedes is a complemento del nombre, and thus just a modifier.)

This is a difference with the way of counting in English (I'm afraid,) and may help solve your other concerns.

Alguno de ustedes is singular. The emphasis is put in alguno and may mean any of you or a few of you.

4.

I hope this one was clarified in no. 1: if you use alguno you mean a small number (a few, one or two, or even any[one], by this meaning:

5.

The key is that algún/a here means any: Do you know any cheap hotels? Of course, algún is singular and so must be hotel.

6.

Alguien and alguno may be synonyms by some meanings, and, up to a point, they can be used interchangeably, practice will tell you when:

Answer 2

Wow, this is a huge question. I'll try to answer, but please try to make them shorter.

Okay, it seems that you've got a big mess here, but you're almost right, so we just have to "straighten" it out a tiny bit. I think you just need to sort them up and draw the lines that separate them well.

First of all, you should set a clear distinction between the determiners and pronouns.

Determiners are {algún, alguna, algunos, algunas} while the pronouns are {alguno, alguna, algunos, algunas}. Of course they correspond to genders and plurals, as you can easily tell. Check that they are the same except for the masculine singular (algún vs. alguno).

Determiners

As determiners, algún/alguna mean someone, as in certain one of the group under consideration.

This explains (2) algún idiota = one idiot / certain idiot (or "alguna idiota", which would mean that you know it was a girl); and also (6): algún hotel = any hotel / certain hotel.

Their plural form is more easily translated as "some" or "any".

Algunas cosas = some things / certain things.

Pronouns

As pronouns, they work in a very simlar way as any other pronoun. They just replace the equivalent name.

"Alguno" or "alguna" mean "someone" or "one of those of the group".

(4): ¿conoces alguno más? = do you know any other else?

and "algunos" / "algunas" is again "some/any".

"Algunos son verdes" = some of them are green.

Alguien

Nice question. "Alguno" and "alguna" are more likely to be applied to objects, although they can be used for people.

The word "alguien" is less definite, "less pointer".

Check ¿hay alguien? = is there anybody there? vs. ¿hay alguno? which would be interpreted as "is there anyone OF YOU?"

Pronoun + de

The group "alguno+de" and its forms can be considered as a single entity, but it is actualy quite literal.

Alguno de vosotros = certain one of you, someone among you.

Algunas de las chicas = certain ones of the group of girls / some of the girls.