for oneself、by oneself、beside oneself、to oneself、of oneself、in oneself有何分別？

(1) for oneself指「為自己」或「自己做」，例如：

Man in ancient times had to do almost everything for himself.

古人幾乎每件事都要自己做。
(2) by oneself指「獨自」，例如：
I did it by myself.
我獨力做那件事情。
(3) beside oneself指「忘我」或「發狂」，例如：

He is beside himself with joy.
他喜歡得發狂。
(4) to oneself指「給自己本身」或「只給自己」，例如：

I kept the secret to myself.
我把秘密藏在心中。
(5) of oneself指「自動」或「自發」，例如：
The door opened of itself.
門自動打開了。
(6) in oneself指「本身」或「本身的性質」，例如：

These substances are not poisonous in themselves.

這些物質本身沒有毒性。
（A Dictionary of Modern English Usage）