"How is it?"
Yes, it is, and sometimes people do not speak colloquially. E.g. in a hotel or restaurant, you'd likely hear いかが
While「どうですか」might be more "colloquial", it's not any less polite or informal than「いかがですか」.
How is your health (condition)?
How about talking to him (or her or them) directly?
These expressions can be used in both polite and casual circles.
as a generic rule, i always learn the colloquial/informal first, as i will likely only be speaking with people my age (16-26) however, this is because of my american mindset and our 'respect' system here. I'm only good at speaking informally in russian right now, but understanding that japanese is a very different system where honorifics sometimes mean even more than what is actually being said, it might be true that, for japanese, learning the formal and proper way before the informal is very important like "anata" being extremely rude if said to anyone whom you wouldn't be comfortable pooping in front of.
imagine if "anata" is accepted, and you could go through an entire course thinking "anata" is totally normal and the go-to word for 'you,' you go to japan, find someone you really respect and say 'anata' and they become extremely offended. oh wait, it is accepted, and many of us aren't understanding the importance of NOT USING あなた unless with extremely close friends.
yes, i agree a system should never mark it wrong if it's correct, and this answer should also be accepted, but there should always be a reminder of the proper form and that saying things like anata could be very offensive.
This is more about how Duolingo works rather than whether or not more/less formal phrases should also be accepted. You sort of need the sting of INCORRECT, because we are learning without a human teacher. A Japanese language teacher can freely assume whatever role is necessary for the grammar of the current lesson and can act offended when you rely on incomplete assumptions; on Duolingo we have no such luxury.
thanks juggler, that helped me a lot. i was thinking of "ika" like "goes" and had the wrong meaning in my head, this cleared it up for me.
show us the KANJI. sometimes it can actually be bad for learners to not see the kanji, i could have gone weeks with the improper definition and had a permanent thought process i have to go through only because you don't at least give us optional full kanji.
now seeing the kanji, and only because of seeing the kanji, (thank you) i understand that this isn't ika like "does it go"? like the french would say, but rather "how is it"? literally, the same as how "kak" in russian means "how / similar to" all in one word.
Sometimes the kanji for a word is so rare that you won’t ever see it in a contemporary real life situation. It’s not always helpful to have the kanji. If it is helpful for you, you should definitely download a dictionary app.
I recommend “Japanese” (red icon with white 日本語 word written vertically on the right side). It’s free, gives important information like ‘usually only written in kana’, shows possible and alternative kanji and readings, and gives example sentences.