I notice these two words come out frequently, but the meaning seems like be different. Who can tell me what is the difference.
If possible give me some examples too.
These are two totally different words in Chinese. Be careful about the writing of them, then you will know the difference between them, just like the English words "pee" and "pea".
己, for example:
自己 means Myself
己見 means my opinion
己身 means my body
已 for example:
已經 means: Already
已為 means: have become, as in "已为人妇"
已婚 means: married already
己, as a single character, means "self". Since 自 has the same meaning. the 自己, as a noun in a sentence, means "self".
已 as a single character has multiple meanings, which I won't explain much here. 自已, as a verb, is only used in genitive sentences and means (cannot) control my (or her or his) motion. For example:
We can say: 我愤怒地不能自已。 他激动地难以自已。 她悲伤地无法自已
We don't say: 他自己了激动的心情。
An ultimate example: 我听到自己被耶鲁大学录取的消息时,激动地无法自已。
Remember, 自已 is only used in negative sentences and only means (cannot) control the motion. This is because of the 词语的固定搭配 and 用语习惯.