"These girls are famous."
Yes, we know, but we are not dealing with a pronoun here, but a noun: 女の子
What confuses us noobs is that we didn't expect to have たち attached to a noun, but here we have: 女の子たち
Just using 女の子 is flagged incorrect by Duo (この女の子は有名です is wrong according to Duo).
What's up with that?
Hoping someone could shed light on this.
As an American that studied French for 10 years through school, I've learned that one tends to learn more about their own native language's grammar while studying a different one. With that in mind, I would put forth the notion that "this girl" is in fact a pronoun rather than a noun.
Pronouns exist to take the place of a noun, and, in many cases, is used to shorten the sentence. "Girl" is without a doubt a noun, but the topic is not the "girls" but rather "these girls." The "this" changes everything. No longer are we talking about a generic group of girls, but instead about a specific girl. We can refer to these girls properly using names, but for brevity sake we use a pronoun "these girls".
Let's say we have two girls named Ashley and Amber. Ashley and Amber are members of an idol group named something like "Purr Cat Nuzzles". We can then refer to the singular group "Purr Cat Nuzzles is famous!", or we could refer to the members like on "Ashley and Amber of Purr Cat Nuzzles are famous, you know." Assume you are a huge fan of this group, and you drag your non-believer friend to a concert. While there, they don't understand why so many people are present. At this remark, you turn to your friend and while pointing at each idol member in turn you say, "Amber and Ashley are famous, you know!" Taking it one step further, you could use "they," but I think I would use "these girls" to specify who I am referring to.
That is a very long winded way of saying that "these girls" is a pronoun so たち can be used. Fun fact, "what" is a pronoun. As is "whom". All because they take the place of some other noun. I looked up the term. In English, it's relative pronouns. Fascinating grammar that is used.
I'd argue that in the case of "this girl" the word "this" is modifying the noun "girl" as an adjective. Sure, it's not as specific as calling the girls by name, but don't you think that you're stretching the term "pronoun" a bit, especially since it takes one word modifying another to get your "pronoun" of two words?
たち (in kanji: 達) is refered as a "pluralizer suffix", but actually it isn't exactly that, but more like "a/the group of".
- この女の子 = this girl
- この女の子たち = the group this girl is part of; this girl and the people around them.
It can be "these girls", or maybe not; この女の子たち can be all young males that go aroung her like butterflies.
It's safe to translate "these girls" as この女の子たち; but it isn't safe to assume otomatically that この女の子たち will always translate as "these girls".
デゥオリンゴの緑色の鳥達 is not a lot of "Duolingo green birds" but rather "the people around the Duolingo green birds" (we all here)