NOW

　　I am now(=at this moment)reading a novel.

　　I am reading a novel now(更为强调).

　　He lost all his money in gambling.

　　Now(用作连接副词，对前面的话加以解释，或只引起注意)this money he had borrowed from his aunt.

　　AGAIN

　　I again(= once more)tried the project.

　　I tried the project again(更为强调).

　　He is a scientist，and again(=besides，用作连接副词)he knows seven languages.

　　SO

　　I told him so(= the same thing).

　　It is raining，so(= therefore，用作连接副词)I can't go out.

　　INDEED

　　He knows a lot of things indeed(用来加强语气).

　　He is，indeed(系动词 be之后)，the best man I know.

　　Indeed(和 but连用)， he knows a lot of things，but he is selfish.

　　ONLY

　　I can tell you only(放在宾语前面)this(= nothing else than this).

　　He is very kind，only(= yet，用作连接副词)he doesn't know how to talk.

　　ONCE

　　I have been there once(= one time，on one occasion).

　　He once(= formerly)lived in the country.

　　Once(= after one time，用作连接副词)I visited the place，I could recognize all the streets.

　　YET

　　He has not yet(= till now)come.

　　He has studied English five years， yet(= but) he is unable to write letters.