介词是描述单词之间关系的词。介词能够描述某物或某人的位置。
- Example
- The cup is on the table.
在上例中,介词“on”描述了杯子和桌子之间的关系。介词也能描述事件发生的时间和方式。
- Example
- I arrived before him.
- Example
- I arrived by bus.
在上例中,介词“before”描述的是“I”何时到达的时间与“him”有关,而介词“by”表示的是乘坐“bus”是到达的方式。介词的主要作用是指示地点、时间和方式。另外,介词也可用于指示所有权和目的。
- Example
- The purpose of this study was to develop a highly heat resistant composite with a carbon fiber base.
- Example
- A book is for reading.
介词的分类
介词的种类 | 介词的作用 | 介词示例 |
---|---|---|
简单介词 | 用于描述位置、地点或时间 | at, for, in, by, off, on, over, under |
双介词 | 两个简单介词连用,通常用于指示方向 | into, onto, upon, up to, inside, outside of, out of, from within |
复合(复杂)介词 | 两个或两个以上的词连用,通常由一个简单介词和另一个词连用,用于表示位置 | in addition to, in front of, at the back of, along with, alongside of, in comparison to, in contrast to |
分词介词 | 分词当作介词使用 | considering, including, excluding, during, regarding, provided |
短语介词(介词短语) | 包括介词、宾语和宾语的修饰语 | for example, for instance, on time, under the influence of |
简单介词
简单介词描述两个词(通常是名词)在位置或时间上的关系。常用的简单介词包括:at, for, in, by, off, on, over, under。
- Example
- The sample was placed under a microscope.
- Example
- We have added additional information in the revision.
- Example
- The board meeting starts at 9:00 am.
- Example
- The sample was placed under a UV light for 30 minutes.
双介词
双介词通常表示方向,由两个简单介词组成。常见的双介词包括:into, onto, upon, up to, inside, outside of, out of, from within。
- Example
- We ran into the apartment.
- Example
- Progressively higher weights were placed upon the composite.
- Example
- The man walked up to the officer.
- Example
- Strange groans came from within the box.
复合(复杂)介词
复合介词表示位置,至少由两个词组成。常见的复合介词包括:in addition to, in front of, at the back of, along with, alongside of, in comparison to, in contrast to。
- Example
- In addition to the tests to evaluate heat resistance, we also submerged the samples in water to test their varying degrees of hydrophobia.
- Example
- I left the package in front of the door.
- Example
- He picked up a soda along with the pizza.
- Example
- Sample 1 demonstrated high heat resistance in comparison to sample 2.
分词介词
分词介词是作为介词使用的分词。它们以“-ed”或“-ing”结尾。常用的分词介词包括:considering, including, excluding, during, regarding, provided。
- Example
- Considering its high protein content, the sample’s resistance to heat was surprising.
- Example
- All of the samples, including the gold composite, were moved to a vacuum chamber.
- Example
- The professor talked about chirality during her lecture.
- Example
- The class will begin in five minutes, provided that all students are present.
短语介词(介词短语)
短语介词(又称介词短语)由介词、介词的宾语和修饰宾语的词组成。短语介词通常以这些词开头:for example, for instance, on time, under the influence of。
- Example
- They arrived at the restaurant on time.
- Example
- You should not drive under the influence of alcohol.
- Example
- For example, composite A did not degenerate when heat was applied.
- Example
- She appreciates the flowers from her children.
用介词结束句子
人们通常认为句子不能以介词结尾。这种假设其实不对。有时,在句末不使用介词会造成句子不够自然流畅。
- 不自然
- Is this the movie about which you told me?
- 自然
- Is this the movie you told me about?
另外,把介词移到句子中靠前的位置能够使句子显得更加正式。
- 非正式
- What journal was your last paper published in?
- 正式
- In which journal was your last paper published?
在上例中,这两个句子都正确,但后一句比前一句更加正式。因此,在学术写作中,介词很少用在句子末尾。
- 非正式
- This is a topic we previously wrote about.
- 正式
- This is a topic that we discussed in a previous paper.
当把介词移到句子中靠前的位置时,需要注意去掉在句子末尾的介词。
- 错误
- In which journal was your last paper published in?
- 正确
- What journal was your last paper published in?
In which journal was your last paper published?
避免不必要的介词
像形容词一样,介词也经常被滥用,即使母语是英语的作者也如此。滥用介词包括两种情况。第一种情况是在句子中错误使用介词。
- 错误
- Where is the other student at?
- 正确
- Where is the other student?
在上例中,介词“at”在语法上是多余和错误的。第二种情况是句子结构的写法不好,使用了太多介词。
- Example
- An understanding of gold composites is necessary for any company in the semiconductor industry at this time.
这种句子最好在结构上重写,使得无需使用那么多介词,示例如下。
- Example
- Understanding gold composites is necessary for companies in the semiconductor industry.