看看它们有区别吗？

be，can，have，has，had（不做“有”“能”实义动词时）做动词时直接提到句首…句中只有动词的句首加按时态加do，does，did。(^-^)下面是not only but also的用法…

主要用法就是谓语动词要遵循“就近一致原则”，Not only the students but also the teacher was invited. 不仅学生们被邀请，而且那位教师也被邀请了。（以下为详细用法）“not only … but also …”是一个并列连词词组，其意思基本等于“both … and …”，但侧重点放在“but also”上，另外该词组使用时须遵守一定的规则，如要求对称，倒装及主谓一致等。以下两个句子往往被看作是欠妥或错误的：
1. *Sitting up late last night,Tom not only read the assignment but also many poems by his favourite poet.
2. *Not only the students but also the teacher were invited.
上述两句第一句欠妥，第二句是错误的，应分别改为：
1. Sitting up late last night,Tom read not only the assignment but also many poems by his favourite poet. 昨晚汤姆熬至深夜，不仅看了课外作业，而且读了他最喜欢的一位诗人的许多诗歌。
2. Not only the students but also the teacher was invited. 不仅学生们被邀请，而且那位教师也被邀请了。 下面就来谈谈正确使用该词组时须注意的几点事项及其常见的几种变体形式。
一、使用not only … but also … 时须注意的几点：
1. not only与but also后面所连接的词的词性必须对等：
(1) Frankin was considered not only an inventor,but also a statesman. 富兰克林不仅被看作发明家，而且被看作