already

already, still

这两个词意思相近,但already指比预想的时间早, still指比预想的时间长。试比较以下两个句子：
The coffee is cold already.
咖啡已经凉了。
The coffee is still hot.
咖啡还热着。

already, yet

这两个词意思相近,它们的区别是：
1.already多用于肯定句,而yet多用于疑问句或否定句。例如：
The guests have already arrived.客人已经到了。
Have the guests arrived yet?客人到了吗?
The guests have not arrived yet.客人还没到。
2.already有时也可用于疑问句中表示惊讶、怀疑,或者表示期望〔预计〕有一个肯定的回答。试比较以下两个句子：
Have you had your lunch yet?
你吃过午饭了吗?(一般疑问句)
Have you had your lunch already?
你已经吃过午饭了?(表示惊讶)
Have you received your invitation yet?
你收到邀请信了吗?(一般疑问句)
Have you already received your invitation?
你已经收到邀请信了吧?
(料想已收到,想证实)
3.yet有时也可用于肯定句中,意思与still相同(仍然,还; 迟早),而与already不同。

already, all ready

这两者读起来音相同,但却绝非一回事。already是副词, ready是形容词; already的意思是“已经”, all ready的意思是“全准备好”, all用以表示程度。试比较：
He is already there.
他已经在那儿了。
He is all ready there.
他在那儿完全准备好了。
The tea is already on the table.
茶已摆在茶几上了。
The tea is all ready on the table.
茶已沏好,摆在茶几上了。