Как бы вы объяснили иностранцу различия между словами "дочь", "дочка", "доча", "дочерь" и "дщерь"?

The word "дочь" has a neutral meaning, without any connotations, like “daughter” in English. Anyway it sounds a little bit strictly, so in everyday speech we use rather the word “дочка", which is derived from the first one and sounds less formally. "доча" is a diminutive, also derived from the general word and wildly used especially when talking to one’s own child; can be compared with ‘my little daughter’. "дочерь" is not used anymore (at least as far as I know) it’s like the Old English word ‘dohtor’. Probably I still can use it when talking sarcastically to a grown-up child, emphasizing the fact that she’s a daughter of mine. "дщерь" is an archaisms, like dhukter in English, out of use, unless for stylistic purposes in lyrics and fiction.