Hello everyone! Been a little while since I've asked a question to the forums. My learning has been coming along pretty well and I'm writing sentences to communicate with others. A common problem I ran into in my writing is knowing when to use Tiu vs Tio for "that". A very basic question but I could use someone knowledgeable giving me their insight on the subject. Dankon!
- use "tiu" if there is a noun after it ("tiu libro estas bona")
- use "tio" is there is no noun after it ("tio estas bona")
Also, use "tiu" when referring to humans ("tiu estas mia amiko").
"tio" means "that" as a pronoun. It stands by itself.
"tiu" means "that" as a determiner; it usually stands in front of a noun, like an adjective.
However, like adjectives, it can also be used by itself. In English, you usually have to use the dummy noun "one" in such a case: "La blua estas granda = The blue one is big". Similarly with "tiu" in that case: "Tiu estas granda = That one is big".
In such a case, there is still some sort of noun implied. You are picking out one object from a group of similar objects -- for example, there might be a blue book, a yellow one, and a pink one and you want to say that "the blue one is big" -- then you know that you are talking about the blue book. Similarly, you might say that "that one" is big -- you know that you are picking out one book from a group of books. Then you could say "tiu estas granda", as shorthand for "tiu libro estas granda".
But if you are just pointing at something, without saying that it is a particular one out of a group of similar objects (e.g. one book out of many), then "tio" is appropriate. "That's a book!" - "Tio estas libro!"
Also, "tiu" has a plural version "tiuj" - both in front of noun ("tiuj libroj estas grandaj") and when used with a noun that's not mentioned ("tiuj estas grandaj" -- those (ones) are big).
But "tio" does not have a plural -- because you are not referring to specific objects (out of a group of similar objects), but are talking about something new and unspecific, so you don't even know whether it's one thing or many.
So you might say "Tio estas libroj" - "Those are books". You can't say "Tioj estas libroj."
So, can 'tiu' and 'tio' also function to mean "this"? I know there are many contexts where, in English, you could interchangeably say "what is that/this" or "I like this/that one". Or should you always (formally) say "tiu cxi [libro estas mia]" and "tio cxi [estas mia libro]"?