1. He not only speak English but also French.

    他不但会说英语，而且会说法语。

    2. This word may be used both as a noun as well as a verb.

    这个词既可用作名词，又可用作动词。

    这些病句的出现，说明没有掌握好英语里的某些对称结构。

    对称结构就是它们所连接的应是两个结构相似、语法功能相同的句子成分的一种结构，英语中最常见的对称结构有 both … and, either … nor, not only … but also, not … but, as well as, not just … but also 等。学习和掌握对称结构，我们需要注意以下几点：

    1. 避免连接不对称词语。

    病句 1 中 not only 后跟的是动宾词组 speak English, 而 but also 后却接了个名词 French 。这样连接的两个语言单位就不对称，这是运用对称结构最忌讳的。

    病句 1 可改为：

    He speaks not only English but also French. 或： He speaks French as well as English.

    2. 注意每一个对称结构的固定搭配。

    病句 2 中错将 both 与 as well as 连用了，而 both 是同 and 结合在一起的。改错时，将病句 2 中 as well as 改为 and 即可。

    3. 当对称结构连接两个平行的主语时，要注意谓语动词在人称和数方面的不同要求：

    （ 1 ） both … and 连接主语时，谓语动词应是复数形式。例如：

    Both Polo and Tom are encouraged to use their own language.

    （ 2 ） as well as 连接主语时，谓语动词需与前面那个主语保持一致。例如：

    John as well as his parents is in trouble now.

    （ 3 ） either … or, neither … nor, not only … but also, not just … but also, not … but 这几组对称结构连接主语时，谓语动词需与后一个主语保持一致。例如：

    Either you or I am mad.

    Not only you but also your teacher is proud of your success.

    （ 4 ） as well as 与 not only … but also 连接两个对称词语时，侧重点正好相反， as well as 侧重的是前一部分，即：不仅 A 而且 B 。试比较：

    It took great imagination as well as patience for Anne to teach me to speak.

    安妮以极大的耐心和想像力教我说话。（侧重点在前而的 imagination ）

    It is therefore possible to say not only what the weather is like at present, but also what is likely to happen in the next day or two.

    因此它不仅报告当天的天气情况，而且可以预报未来一两天内可能发生的天气情况。（侧重点在后面的 what is likely to happen in the next day or two ）