Colloquial

In this little user box from Wikipedia is the phrase "This is the apple I want to eat" in different levels of language.

co-1 is the most colloquial form
co-2 is simply informal
fo-1 is formal language, as in tv or news papers
fo-2 is archaic, poetic and language used in declarations and official papers

The only difference between fo-1 and -2 is is the pronoun de becoming da. Da is an accusative relative pronoun, because the verb "to want" in this context has its object in accusative and its subject in dative. Da vis meiğ i fogamesin (which-acc likes me-dat into my eating) is a confusing construction, and thus in most cases the object of the phrase (which is in reality its subject, because the apple likes me into my eating, which means it is what I want) is refered to with nominative, de, in this instence.

The difference between f- and c- is mainly the way the word apple is emphasised (with ne and da) and the verb to eat (fogan) is replaced by moinis. The word "to want" is also changed, from ůlog (to want) to min (to feel like), which both are very similar, and in many cases equal.