1 and 出现在两个及以上的词，词组，或者句子之间，将它们连接起来。在正式的书面英语中，and不能出现在句首。在非正式的英语中可以。
We should expand our product lines and launch a new ad campaign.
We should expand our fragrance, cosmetics, and perfume lines.
2 as well as 和 and 意思相同。它出现在两个词或词组之间， 将它们连接起来。但是不能用它来连接两个句子。也不能用来连接两个以上的词或词组。
We should expand our fragrance line as well as our cosmetics line.
3 also 和 too 用于在陈述完第一个观点之后，又补充第二个观点。also 可以置于句子的很多个地方，但是不能放在动词与宾语之间。 too 几乎总是置于句尾。
First idea: We should launch a new adverstising campaign.
Second idea: We should target a younger audience, too(also).
We should also target a younger audience.
Also, we should target a younger audience.
4 in addition 和Furthermore 用于介绍完第一个观点之后又补充第二个观点。它们与too和also 意思相同，但是更加正式。它们通常置于句首，而且有逗号将它们与句子的其余部分隔开。
First idea: We should launch a new adverstising campaign.
Second idea: In addition(Furthermore), we should target a younger audience.