So that doesn't really answer the question of whether the language is consistent on this between "you are angry" and "you are my friend".
You didn't specify which language you mean. I spoke about an example from Radical Honesty. That's not really a conlang but simply a way to use the English language and not even one that requires you to use certain phrases to express yourself. If you mean my conlang draft every sentence should end in a evidential and that goes for both of those sentences. Apart from that I don't think that "you are angry" is a good construction. I wouldn't want to have "to be" involved in that construction.
I spoke about an example from Radical Honesty. That's not really a conlang but simply a way to use the English language
Sorry, I misunderstood. But I think the same question can be asked even if it isn't a language. "You are angry" must be expressed using words that recognize that you are making a conclusion about someone's anger. Must similar sentences about other conclusions be expressed that way? Or does this requirement apply only to "you are angry" while there is no requirement for "I conclude my car is out of gas" or "I deduce that you are motivated by friendship"?
I'm working on a conlang (constructed language) and would like some input from the Less Wrong community. One of the goals is to investigate the old Sapir-Whorf hypothesis regarding language affecting cognition. Does anyone here have any ideas regarding linguistic mechanisms that would encourage more rational thinking, apart from those that are present in the oft-discussed conlangs e-prime, loglan, and its offshoot lojban? Or perhaps mechanisms that are used in one of those conlangs, but might be buried too deeply for a person such as myself, who only has superficial knowledge about them, to have recognized? Any input is welcomed, from other conlangs to crazy ideas.