too ; also ; either ; yet的意思

too和also都是“也”的意思，唯一不同的是too用于句末，
eg.He is a student,and i am a student,too.
而also用于句中，eg.He is a student,and i am also a student.
而either也可以解释为“也”但是是用于否定句中的，eg."I haven't seen this film, and my brother hasn't either."
"我没有看过这部电影,我哥哥也没有。"

yet
adv.
还; 仍然; 尚
Much remains yet to be done.
还有许多事情要做。
He has not yet heard the good news.
他尚未听到过这个好消息。
He has never yet told a lie.
他还从来没撒过谎。
John is alive yet.
约翰还活着。
[同比较级连用]还要
You must work yet harder.
你工作还要加把劲。
[疑问]已经
Has the school begun yet?
已经开学了吗?
[同连接词连用]然而, 可是
It is strange, and yet it is true.
是奇怪, 可是真的。