1,查奇摩字典all它是代名詞,形容詞,副詞,名詞,但又是det.請問det代表何詞類. 2,Buoyancy 與buoyance有何不同?

All:-when followed by the def art,demonstratives, possessives, and cardinal numbers:-eg:-All horses are animals but not all animals are horses .All the five of them are hard workers .All--->them--->hard workers----->Hence "det"(grammar) is used  as word that "determines" or limits the noun that follows as a determiner.:-eg:-all (pronoun)-----(pronoun)----->them------>hard workers.
buoyancy n., is the power to float or keep things floating:-eg:-
Dead Sea salt water has more buoyance than fresh water.---
---figuratively is used as lightness of spirits; power to recuperate; Of the stock market is used the tendency of prices to rise and fall:-eg:-
Tencent has the tendency to rise.
buoyant adj., is used  to be able to float or to keep things floating;(figure) used as light-hearted;eg:-with a buoyant step after drunk in Lan-kwai square Bar-District.eg:-
With a buoyant(adj) step of the stock market, Tencent has been maintaining high prices buoyantly(adv)