Hey so how can I discover likes, dislikes and fav. food of the characters?

[Hansell1001]

Dont enlist them or dont give me links.

I just wanted to know if there is an in-game guide somewhere beyond the animal appearances and what you must infer they eat by the look of them.

I just want that for completionist purposes and if there is an achievement related to that.
And before I say goodbye to them. Two of them want to go already but I havent discovered some likes, dislikes and favs.

[rmsgrey]

a) paying attention to things they say can help. For example, Gwen straight up tells you that she loves a particular dish.

b) sometimes there are hints in the world if you pay attention to where you find that spirit and what else is around. For example, one spirit is on the same island as a chest containing the recipe for their favourite food.

c) there's at least one quest where you find out some spirits' favourite foods (by asking them). Other quests have you give a spirit their favourite food without outright telling you it's their favourite.

d) general likes and dislikes usually make sense for their character, so someone who prides themself on being plain-spoken and working class might like plain food, while someone who is openly eclectic in their tastes is liable to favour more exotic fare.

e) experimentation and trial and error will eventually stumble across all a given spirit's food preferences.

There's no universal rule for how best to find out a given spirit's tastes within the game.

[CtenosaurOaxacana]

rmsgrey's list of pointers is good.
Although I should also add that many (most? all?) spirits will eventually outright
tell you their favorite food &/or at least one preferred dish type after awhile
if you haven't given it already. Not just Gwen.

But even if you're having trouble, don't worry about it.
There's no rush in learning their food preferences.
You can wait until right before you bring them to the Everdoor if need be.
The exception to this would be Daria the bat, because
you can only interact with her on the island,
plus one last chance right before you take her to the Everdoor.