有读者问这样一道选择题：
(1)They asked to_________us in buying a gift for our teacher on his birthday.
A. join to B. join C. join with D. join up
根据所学课文应选 B,但我们在某些英语词典中见到这样的说法：
(2)He joined with me in the undertaking.
(3)My brother joins with me in kind regards.
(4)join in with sb.to take a risk
请问join sb.in sth., join with sb.in sth., join in with sb. 这三者有何区别？
上述三种说法都有“和某人一起参与”的意思。 join sb.in sth. （或 in doing sth.）与 join with sb. in sth. （或 in doing sth.）二者不仅意义相同，而且可以互换。例如在《牛津现代高级英语学习词典》中就有这样的例句：
(5)Mother joins （with） me in sending you our best wishes. （介词 with 可有可无）
由此可见，上述选择题选 B 和选C 都不错。但美国英语则似乎多用join with sb. in sth. （或 in doing sth.），例如有的美国词典就指出这种 join 之后常接介词 with。又据英国牛津大学出版社出版的一本习语词典说， join with 多用以表示吊慰和同心同德，如：
(6)We all join with Mr.and Mrs.Page in their sorrow.
(7)We must join with the Party in its struggle for freedom.
关于 join in with，据上述习语词典说，它除用以表示“和某人一起参与”外（如上述例[4]），还可以表示“与某人共同负担费用”，如：
(8)We joined in with another family to buy the boat and share it for our holidays.
(9)We may have to join in with the other college in building the library.
