There you go, more indisputable evidence that Chinese has grammar, and a good example why you cannot just study pinyin without at least becoming familiar w/ the characters.[/quote]
I agree that Chinese has grammar. Your second statement is unfounded. The three graphs you cite may simply be an orthographic convention designed to differentiate between three uses of the same particle. If the three are really different words, we would look at their phonetic history to see if they had different pronunications at one time.
Also, you could have easily given your examples and explanations in pinyin and the original poster could have understood what you meant.
The particle ‘de’ has three distinct uses:
‘de’ as an adjective particle, as in “hongse de maozi” “red-colored hat”
‘de’ as an adverbial particle, as in yongyue de canjia “take part enthusiastically”
‘de’ asthis complement of degree Tetsuo was talking about, which can follow a verb as in zuodehenhao “well done”, or redeyaoming “wicked hot”.
An important rule to remember is that the 2nd “de” is optional and may be omitted, while the others cannot.
There is some kind of subtle modal difference when your second example is used with or without the ‘de’. For example, you’ll often see people being urged to “Yongyue canjia”. In this case I think the ‘de’ cannot be used. Any native speaker care to weigh in?
And if I remember correctly. China does not use three different characters to distinguish these different uses–more evidence that this orthographic distinction is arbitrary rather than necessary.