书摘--冗余、形式主语VS实际主语、介词及冠词使用问题

写作中的冗余句式：  
在实际写作过程中，有一些句式本身就可能带来不简洁的效果。比如常见的“there be”句型，我不太推荐使用。一方面是因为“be动词”是弱动词，而真正的动作放到了别的词上（后面的章节会讲到）。另一方面是因为这一句型不够简洁，细心的话，不难发现任何以“there be”开头的句子，都是可以省掉这个词组的，比如“There are two children playing”就可以直接写成“Two children are playing”。又如“There is no significant relations between A and B”这句话是非常常见的结果描述，通常我会写成“no significant relation is found between A and B”或者主动语态“ We found no significant relation between A and B”。   
另一个不够简洁的句型是被动语态。美国心理学会（APA）建议尽量不用被动语态，主要有两方面原因：一方面是我们要强调动作的主体，而被动句通常省掉了主体；另一方面是弱动词的问题。例如，很多人在描述被试的情况时，经常用“50 participants were recruited from a college”这种表达方式，而我一般会改成主动语态：“We recruited 50 participants”或者“Our study included 50 participants”。在中文写作中，很多人不习惯说“我”“我们”，但应该明确你才是研究的主要实施者，英文写作中不要怕用“I”和“we”。
“This finding made us speculate that”不如改成“We speculate that”或者“This finding suggests that”。   事实上，任何以“previous research has shown that ...”或者“×××were reported（by previous research）”作为开头的句子都可以省略这两种表述。因为在科技论文里，有文献引用的前提下，你说出一个结论，读者基本默认是一个基于科学研究的结论。   
语义上的重复：
如“stimuli in Study 1 were repeated again in Study 2”，“repeat”本身包含了“again”的含义，所以应该去掉“again”，或者改成“presented again”。又如“to compare the difference between the two groups”，这里的compare和difference存在语义上的重复。写这句话的学生是受到“比较两组差异”的中文表述习惯的影响，而准确的表述应该是“比较两组”或“检验两组的差异”，所以可以改成“to compare the two groups”或“to examine the difference between the two groups”。   
形式主语和实际主语不一致的问题：
下面举几个常见的例子。（1）The planned project will run 3 experiments.问题：这可能是描述实验设计时经常用到的句式。问题在于“run experiment”的形式主语应该是“experimenter”，也就是“authors”，在文章里面建议用第一人称（“we”）。建议改为：We will run 3 experiments.或者把project作为主语，改为：The planned project contains/includes 3 experiments. 
（2）Based on previous research, we expected that…….问题：这个例子在论文中更加多见，问题也在于形式主语和实际主语不一致。建议改为：Based on previous research, the current study was expected to…….或者改为：On the basis of previous research, we expected that……. 
（3）To examine the effect of autistic traits on the trade-off between accuracy and monetary rewards, forty-five participants were divided evenly into three groups.问题：“examine”的主语不是“ participants”，而应该是“we”或者“this study”。建议改为：To examine the effect of autistic traits on the trade-off between accuracy and monetary rewards, we divided forty-five participants evenly into three groups. 
（4）To compare the differences of the percentage of recurrence between groups, each participant's percentage of recurrence at different time lags was subtracted by their baselines to make the average percentage of recurrence in the ASD and TD groupcomparable.问题：这句话的问题也是形式主语是“we”，而不是“participants”，所以尽量用主动语态，以避免这个问题。改为： To examine the differences of the percentage of recurrence between groups, we subtracted each participant's percentage of recurrence at different time lags by their baselines to make the average percentage of recurrence in the ASD and TD group comparable. 
（5）To evaluate the prediction performance, the sensitivity,specificity, and area under the curve (AUC) of the receiver operating characteristic curve (ROC) were calculated.问题：与上一例同理。改为：To evaluate the prediction performance, we calculated the sensitivity, specificity, and area under the curve (AUC) of the receiver operating characteristic curve (ROC).   
介词使用注意：
比如“reply the email”“apply the scholarship”，问题就在于缺了介词“to”和“for”。   形式主语与实际主语不一致，与句子成分不搭配：
 冠词使用规则：
（1）不要让一个单数可数名词单独出现，一定要加一个不定冠词或者定冠词。这几乎是最容易发现的冠词错误了。 
（2）如果是复数名词，就看是泛指（不加定冠词）还是特指（加定冠词）。这听起来很简单，但实际运用中很容易出现问题，所以要加以重视。