Alguno can function as either an adjective or pronoun.
As a pronoun alguno (and alguna) means someone/somebody/one, and as a pronoun algunos (and algunas) means some. For example, hay alguno aquí means there is someone/one here, and hay algunos aquí means there are some here.
In this sentence, Fue alguno de ustedes, alguno is a pronoun meaning one (of you).
As an adjective, algún, alguna, algunos, algunas mean some (or any in a question). For example, algún día means some day, and algunos problemas means some/several problems.
As an adjective after the noun, alguno means whatsoever/none/not at all. For example, sin motivo alguno means for no reason whatsoever.
Both alguien and alguno can mean someone. While alguno can be an indefinite pronoun or adjective, alguien functions only as an indefinite pronoun that means someone/somebody (or anyone/anybody in questions).
alguien me dijo que la vida no es justa (someone told me that life is not fair)
siempre hay alguno que protesta (there is always someone who complains).
I don't know how interchangeable these are as pronouns, but alguien seems more common as someone, and alguno seems closer in meaning to some.
I'm sorry, but in the 46 comments I've read, I still do not get it. What is the difference between saying "Fue alguno de ustedes" and "Fue uno de ustedes"? My question is specifically about the use of "Alguno" vs "Uno" in this context. Does the use of Alguno and Uno in this sentence convey the same meaning or is there a commonly understood difference between when one is used vs the other?
"Fue alguno de ustedes" and "Fue uno de ustedes" mean the same thing, out of a group it was one of you. As for alguno vs uno, it depends on the context, sometimes (as previously shown) they work the same way, others they don't. If you read my previous comment you should have seen that I said that if you wanted to say "You were one of them." you could not use "Fue alguno de ustedes" but "(él ) Fue uno de ustedes." because "alguno" has more of a "pluralized" sound so if I want to be specific about the fact that you and only you were part of them you use uno. "El fue alguno de ustedes" to mean that "He was one of you" sounds weird to me, as if we were talking about characters and there are three characters and you are telling to those three characters that he in the past was one of them (as in taking their role). I don't know if I'm explaining myself but I think what I'm trying to convey is clear.
I appreciate your response and your previous comment on this. I am afraid I am still not 100% certain as to the proper way to distinguish when to use each however, I do now understand that they have the same basic meaning. As with many of the lessons in Duolingo, I will continue to repeat lesson after frustrating lesson until I can sing these sentences in my sleep. From what I have found on the internet, Alguno when used as an Adjective = "some" and when used as a pronoun like in this case, it means "one." Beyond that, I am afraid I still am not clear.
From your responses, I think I understand that if I wanted to say something like, "I will see you again one day." Then Alguno dia would be more appropriate to convey the meaning of "one day in the future" / "some day in the future" as opposed to saying I did something for ONE day where UN DIA would be more appropriate (I guess because there is no implied plurality/possibility for "the day" to be a loose / floating day).
I can see what your saying in an example that one but not in this question.
In your example, "I will see you again one day," the meaning could also be "I will see you again on one, and only one, day." This meaning is similar to the mathematical and logical phrase "if and only if," which means one unique time and place after one specific condition. In my comment to Lavmarx, I wrote about how "alguno de ustedes" could mean "someone," out of the (group of) all of you. Equally, perhaps "alguna dia" can mean "someday." In other words, the condition is one and one day only, but the time and place are NOT specified.
From what you say in this comment, it sounds as though you are saying that when "alguno" has more of a pluralized meaning, it could also be translated as "someone." In other words, "Fue alguno de ustedes" would have the denotative meaning of "It was someone of you" and the connotative meaning of "It was someone, out of all of you." Do you think I am on the right track here, or did I stretch the rubber band too far? BTW, SFJuan's posting and this posting tied it together for me. Thanks.
Reading through the long list of comments, I saw that "He was one of you" is also accepted. Strangely, it rejected my "She was one of you", which I will report. I also find "It was one of you" to be a bizarre translation. As a native English speaker I am trying to think of a time I would actually say something like that. About all I can come up with is a situation where you are speaking about a trans person who prefers being referred to as "it". I guess we also sometimes refer to animals as "it", but when we are close to them, such as a pet, we usually call them "he" or "she".
I should have used "fue" instead of "Fuiste" to make my point, but I wasn't talking about any of those words, I was talking about "alguno", saying ‘Fue alguno de ellos.’ to tell someone they where part of them is like saying "You where some of them" in English, You should use one: "Fue uno de ellos."
To clear a bit more, for native speakers the stand alone phrase ""Fue alguno de ustedes." or "Fue alguno de ellos." will mean that someone out of a group is the culprit of something, if the phrase was made to mean that "usted/ella/él" or "tú" as I said, was a part of them, you would not use "alguno" but "one" and normally the subject is not omitted.
María: ¿Quién rompió la ventana?
Juan: Fue alguno de ellos. (fue uno de ellos)
María: ¿Quién rompió la ventana? ¿Fue alguno de ustedes?
Juan: Odio a los criminales!
María: Alguna vez usted fue uno de ellos, no los juzgue.<pre>
(Alguna vez fuiste uno de ellos, no los juzgues.)</pre>
This is wrong. In your example, the word "you" must be plural because the "someone," which is singular, is a part of the whole group of "you." Also, it is not colloquial English to use the word "someone" here. Instead, native speakers use the word "one," as in "It was one of you."
When anyone is learning a language, it's not a mistake. Rather, it's an area where you need to see the whole picture. It has to do with how English treats number.
1) By definition, the English word "someone" is singular in number. 2) By definition, the English word "you" can be plural or singular in number. 3) By definition, compound words are two words joined together because they have a specific meaning when used next to each other, a meaning that they do not necessarily have when they are not used together. Some examples of English compound words that were originally separate words: birdhouse, firetruck, firefly, doghouse, treehouse, dollhouse, dragonfly, screwdriver, snowflake, proofread, sleighride, everyone, anyone, anyone, anybody, nobody, awhile, arrowroot, overlap. Notice that compound words can be combinations of different parts of speech, such as nouns, adjectives, and/or verbs. 4) The English word "some" can be either an adjective or a pronoun. It is indefinite in number, which is defined as "incomplete/indefinite in quantity." The concepts of "indefinite" and "uncountable" overlap sometimes, but remember, sometimes these concepts don't overlap. For example, if I say "Take some cookies," and there are ten on the plate that I am holding in front of you, then those cookies are countable. Still, whether it is being used as a pronoun or as an adjective, the word "some" is plural in number. 5) The English compound word "someone" is the combination of the English adjective "some" and the English pronoun/noun "one." The reason they are joined as a compound word is because the specific meaning is "one and only one person, but his or her identity is unknown." Because of the "one," the number is singular.
You were correct in identifying that the "some" that is part of the word "someone" can indicates a plural number, for example, as in the movie title: "Some came running." What you didn't yet understand is that the "some" of the compound word "someone" is being used as an adjective/modifier of the pronoun "one" in order to indicate not uncountability but rather uncertainty as to "which one" is under discussion. In other words, which person is "indefinite," but we know that it is "some" person.
Hey Linda, thank you very much for writing such a long post about English grammar, take a lingot and an upvote ;) However, you are not 100% right: I have already understood that the word "some" can refer to the above mentioned uncertainty. If I was speaking about "more than one person out of a group of many people", I would translate it by: "Fueron algunos de ustedes/vosotros" (even though I am not sure if this is good Spanish - by the way: how would you say this in English? It were some of you? It was some of you? Neither sounds good to my ears :D ) I have also understood that you do not say "it was someone of you", because it "doesn't sound right". But I don't see what "rule" or logical thinking (other than having a native speaker tell you that it is not idiomatic) should tell you not to use "someone" instead of "one" The "speaker" in the above sentence could be unsure about which person of the group "it was" (which would at first glance justify the use of the word "someone"). Example: a teacher who is talking to a group of children and knows that one of them did a bad thing, but not who of them and is thus asking them/the person concerned to admit it or else he will punish all of them. As I said: I will remember to say "one of you" and not "someone of you", but not because of your very nice grammar lesson, but just because two independent native speakers have told me so ;)
The preterite tense is identical for "ser" and "ir". Strange, but true.
ser preterite: fui fuiste fue fuimos fuisteis fueron ir preterite: fui fuiste fue fuimos fuisteis fueron
I still remember my hair standing on end when I first found out about this.
In English, when "some" and "any" are used as adjectives, their meanings are often connotatively interchangeable. For example, "Is there some pie left?" and "Is there any pie left?" However, there are fine shades of meaning. "I'll take some pie" differs from "I'll take any pie." The first sentence denotatively limits what kinds of pie you will take, while the second sentence denotatively includes every kind of pie. In polite parlance, "any" is used by supplicants: Any charitable contributions, no matter how small, will be accepted. Similarly, sometimes "any" is substituted for "some" so that a sentence sounds more polite, as in "Is there any way I can help?" The sentence "Is there some way I can help?" has exactly the same meaning, but the sentence with "any" just sounds more polite. Also, "some" and "any" are not interchangeable when used as subjects and/or objects of sentences. For example, compare "I don't want some of them" to "I don't want any of them." Quite a different meaning there!
"Some" is a plural uncountable subject in "Some are coming," and "any" is an uncountable plural subject in "Are any coming?" (As for why English prefers "any" when the sentence is switched from a declarative statement to a question, I have no idea.) To clarify that a singular meaning is meant, the word "one" is added as a suffix to "some," "any," and "every." For example, "Is anyone coming?" or "Is someone coming?" or "Is everyone coming?" BTW, these guidelines also apply to "every."