好的Assignment写作需要不同类型句子的适当组合。过多的短句、简单句会使Assignment写作变得枯燥乏味，而过多的长句、复杂句则会使写作变得浓密难懂。本文致远教育小编为大家分享Assignment写作高级语法使用技巧。
英语Assignment写作中可使用的句子有三种基本类型，即简单句、复合句和复杂句。
一个简单的句子包含一个独立的从句，换言之，一个从句(一组有主语和动词的词)本身就可以表达一个完整的思想。
Example：
Academic writing is a difficult.
It takes a long time to learn.
复合句有两个独立的分句，由一个并列连词(for，and，nor，but，or，yet，so)或分号连接。
Example：
Academic writing is a difficult, so it takes a long time to learn.
Academic writing is a difficult; it takes a long time to learn.
复杂句有一个独立的从句和一个或多个从属从句，从属从句不能单独成为一个完整的句子。它一般包含三种类型，名词从句、形容词从句和状语从句。
Example：
Some experts do not agree that global warming is a serious problem. [名词从句]
Burning fossil fuels adds to global warming, which is one of the greatest threats to mankind. [形容词从句]
He learned academic writing quickly even though it is difficult. [状语从句]
名词性从句
第一种用于创建复杂句子的从属从句是名词从句。名词从句是充当名词的从属从句。有三种类型：that从句、wh-word从句和if/if从句。
1.that从句
that从句是由That这个词引申而来的，很多时候这个词常常被省略。
Example：
Scientists have concluded that greenhouse gas emissions are a serious problem.
Experts have warned governments that reduction in fossil fuel consumption is necessary.
Greene (2016) points out that class size is a key factor in school effectiveness.
The lecturer assured us that the topic would not be covered on the test.
英语Assignment写作中有许多动词后面跟着that从句。下面是一些最常见的列表。其中许多是报告动词，即用于报告他人的单词或想法的动词，以及根据它们是否需要间接对象来决定后面是否带或不带“to”。
子句中动词的时态通常与主动词(即独立子句中的动词)的时态有关。如果主动词用在现在时，从句动词可以用任何合适的时态。如果主句动词是过去时，从句中的动词通常也是过去时。不过这种情况也有例外，那就是某些“基本形式”动词，包括：建议;询问;命令;要求;直接;坚持;建议;建议;和敦促(advise; ask; command; demand; direct; insist; propose; recommend; suggest; and urge)。还有一些形容词后面跟着基本形式动词，例如：可取的;必要的;必要的;重要的;紧急的;重要的(advisable; essential; necessary; important; urgent; and vital)。
Example：
It was concluded that lack of attention caused the accident. [Past + past]
It is agreed that greater attention to the problem will be needed in future. [Present + future]
It is necessary that governments reduce reliance on fossil fuels. [Base form, reduce]
It is recommended that greater precautions be taken in future experiments. [Base form, be]
2.wh-word从句
Wh-word从句由Wh questions组成，由wh-words引入，如who, whoever, what, whatever, where, wherever, when, why, which, how, how long, how much, and how many. 由于这些从句是陈述句(而不是疑问句)，词序应该是主语+动词，不使用疑问句中使用的助动词(例如do、do或did)。
Example：
It is not known where the epicentre of the earthquake was.
The report explains how alpha waves are detected.
It is not known where the substance originates.
3.if/Whether从句
If/Whether从句由yes/no(是/否)问题构成，并由while或If一词引入。可以添加短语“or not”。请注意，Whether比if更正式，因此在学术写作中更常见。
Example：
The results of the experiment determined whether the drug entered human trials.
The results of the experiment determined whether the drug entered human trials or not.
The results of the experiment determined whether or not the drug entered human trials.
It is unclear if the measurements were completely accurate.
It is unclear if the measurements were completely accurate or not. [NOT ... if or not the measurements...]
形容词从句
第二种用来高级语法句子是形容词从句，也称为关系从句。形容词从句是充当形容词的从属从句，换言之，它修饰名词或代词。形容词从句以下列关系代词之一开头。
Example：
who, whom [for people]
which [for non-humans or things]
whose, that [for humans, non-humans or things]
when [for time]
where [for place]
关系从句可以是限制性的(也称为限定性的)或非限制性的(也称为非限定性的)。限制性从句是必要的，因为它为读者识别名词。逗号不用于限制性子句。另一方面，非限制性从句不必用来识别名词。它只是给读者提供额外的信息。由于它可以省略而不失去意义，所以它用逗号与句子的其余部分分开。
Example：
The material which was used in the experiment was impure
[限制性的，因为需要用‘在实验中使用的’这一条款来确定材料。]
The material from the experiment, which was impure, was weighed twice.
[无限制，因为‘不纯洁’一词只提供了有关材料的额外信息。]
简洁清新的标题
第三种也是最后一种用来提高语法水准的是状语从句。状语从句是一种从属从句，用来修饰独立从句的动词，以提供有关何时、何地、为什么、如何、多长时间或多远的信息。它还用于显示对比度。
状语从句可以在独立从句之前或之后出现。如果在前面，需要用逗号分隔这两个子句。如果在后面，就不需要逗号。
Example：
Whenever a tectonic plate moves suddenly, an earthquake can occur.
An earthquake can occur whenever a tectonic plate moves suddenly.