hence / therefore 的擺位用法?

hence = therefore（用來帶出結果，後面都不用逗號）
I think, therefore I am.=我思，故我在。（放在對等的第二個子句之前）
He was not there, therefore he is innocent.=他不在現場，故無罪。
He was hence unable to agree.=因此他不能同意。（放be動詞後面）
The trade imbalance is likely to rise again in 1990. Hence a new set of policy actions will be required soon.
Whatever is hidden is harmful (hence revelation equals security).
European music happens to use a scale or eight notes, hence the use of the term octave.
The Socialist Party was profoundly divided and hence very weak.

It may be possible or not; however, we shall see.表示對等關係的「連接副詞」however，前面用分號，後面用逗號。
Grandfather Dingsdale had sustained a broken back while working in he mines. Consequently, he spent the rest of his life in a wheelchair.
relations between the two companies had, consequently, never been close.
連接副詞不能直接用來連接兩個對等的子句，前面引用的therefore對等句缺了連接詞，應使用分號，並在therefore後面加上逗號，才是完整的正確方式。英美人士有些時候不遵守這些習慣。請參見《新觀念英文法》pp.324~325。