Following this question I am now unsure about the way the concept "one of them" can be expressed. Let's use the sample phrase "one of them is big" as an example.
My understanding so far was that if we talk about people, we say
- Einer/e/s von ihnen ist groß.
while for inanimated things we say
- Einer/e/s davon ist groß.
Now it looks that there are other possibilities:
- Einer/e/s ihrer ist groß.
- Einer/e/s deren ist groß.
and even
- Einer/e/s der ist groß.
Are 3, 4 and 5 right? If so, in which context(s) are they used?
Wir sahen Löwen. Es waren ihrer drei.
"Ihrer" in this context means the same as "von ihnen" (put after "drei" then). Notice the different word order though. As stated by P_S, quite old language, but still used today.