Determiners constitute a small class of words, including "that", "the", "a", "some", number words like "two" or "three", "some", and "various". They occur in noun phrases.
1. 名词前面常常带有the、a或an。这些词被称为限定词。它们标示着名词所指意义的种属。限定词the叫做定冠词，用在单数和复数名词之前。
2. 数词出现在名词前面时是限定词。
3. 限定词出现在名词前面，表示名词所指意义的种属。
an apple一个苹果
twenty books 二十本书
all the book 所有的书
half a chapter 一半章节
the two children 俩孩子
his fourth birthday 他的第四个生日
That film is excellent那部电影很出色
The main difference between count and noncount nouns is whether or not the things they refer to can be counted.
Count nouns refer to things that can be divided up into smaller units which are separate and distinct from one another. They usually refer to what can individually be seen or heard: table chair word remark finger bottle award candidate
Noncount nouns refer to things that cannot be counted because they are regarded as wholes which cannot be divided into parts. They often refer to abstractions and occasionally have a collective meaning: anger furniture warmth leisure education courage progress weather
普通名词所表示的人或事物是可以按个数计算的，这类名词叫可数名词。可数名词分为个体名词(表示某类人或事物中的个体，如worker, farmer, desk, factory等)和集体名词(表示作为一个整体来看的一群人或一些事物，如people, family 等)。如果普通名词所表示的事物是不能按个数来计算的，这类名词就叫不可数名词。不可数名词分为物质名词(表示无法分为个体的物质，如meat, rice, water, milk, orange 等)和抽象名词(表示动作、状态、情况、品质等抽象概念，如work, homework, time, health, friendship等)。
map → maps 地图
onion → onions 洋葱
some water 一些水
a lot of bread 很多面包
Auxiliary verbs (sometimes known as helping verbs) are verbs that are used to assist the verb.
Auxiliary verbs can not be used without a main verb.
Auxiliary verbs can not be used with modal verbs.
Auxiliary verbs are used to make sentences negative.
Auxiliary verbs are used to ask questions.
Auxiliary verbs are used in the sentence structure of the verb sentence.
The 3 most common auxiliary verbs are:
Do - Does - Did
Do is used with the present simple tense. Do-Does are used as part of the sentence structure for negative statements/sentences with the present simple tense
Do- Does are used as part of the sentence structure for questions, with the present simple tense.
Did is used with the past simple tense.
Did is used as part of the sentence structure for negative statements/sentences with the past simple tense
Did is used as part of the sentence structure for questions, with the past simple tense.
Be - Am - Is - Are -Was - Were
Have - Has -Had
DO', 'BE' and 'HAVE' are the English auxiliary verbs used in a negative structure, a question or to show tense.
DESCRIPTIONS OF ENGLISH AUXILIARY VERBS:
助动词有时被称为“辅助动词”。这是因为它们可以说“辅助”了后面的主动词。例如在The old lady is writing a play一句中助动词 is对 主动词 writing起到辅助作用，指明主动词表示的动作还在进行当中。
被动态助动词be
This is used to form passive constructions, eg. 用于被动结构，例如
The film was produced in Hollywood （电影制作于好莱坞）
It has a corresponding present form:它有对应的现在时形式：
The film is produced in Hollywood （电影制作于好莱坞）
We will return to passives later, when we look at voice.在语态部分我们还将回到被动句。
进行体助动词 be
As the name suggests, the progressive expresses action in progress: 如名字所示，进行体表示进行中的动作：
The old lady is writing a play（老妇人正创作一部戏）
It also has a past form: 它也有过去时形式：
The old lady was writing a play（老妇人正创作一部戏）
完成体助动词have
The perfective auxiliary expresses an action accomplished in the past but retaining current relevance: 完成体助动词表示过去完成、但与现在一直有关联的动作。
She has broken her leg（她的腿摔断了）
(Compare: She broke her leg) （试比较：她摔断了腿）
Together with the progressive auxiliary, the perfective auxiliary encodes aspect, which we will look at later.完成体助动词与进行体助动词都表示动词的“体”。这个我们以后还要谈到。
形式助动词Do
This subclass contains only the verb do. It is used to form questions: 这一子类型只包含一个动词do,用于组成问句：
Do you like cheese? （你喜欢奶酪吗？）
to form negative statements:用于组成否定陈述句：
I do not like cheese（我不喜欢奶酪）
and in giving orders: 还用于下命令
Do not eat the cheese（不要吃奶酪）
Finally, dummy do can be used for emphasis: 最后，形式助动词do还可用来强调：
I do like cheese（我的确喜欢奶酪）
助动词与主动词的一个重大区别是助动词从不在句子中单独出现。例如，我们不能将主动词从句子中拿走、只留下助动词。
We use the simple present tense when:
the action is general
the action happens all the time, or habitually, in the past, present and future
the action is not only happening now
the statement is always true
一、构成
一般现在时除主语是第三人称单数时谓语动词要加s外，一律用动词原形。
二、用法
一般现在时表示经常性或习惯性的动作，常与表示频度的时间状语every day, usually, always, often, sometimes, on Sunday等连用。如：
I go to school at 6 every morning. 每天早上我七点去上学。
Summer follows spring. 春天之后是夏天。
The sun rises in the east. 太阳从东方升起。
注意：此种用法即使出现在过去的语境中，仍用一般现在时。如：
I learned that the earth goes around the sun when I was in primary school. 我在小学就学过地球是围绕太阳转的。
Pride goes before a fall. 骄者必败。
I am a teacher. 我是教师。
Peter writes good Chinese but does not speak well. 彼得汉语写得不错，讲的可不行。
Here comes the bus. = The bus is coming. 车来了。
There goes the bell. = The bell is ringing. 铃响了。
1. 在状语从句中用一般现在时代替一般将来时。如：
I will give it to him as soon as I see him. 我一看见他就交给他。
He will come if you invite him. 如果你请他,他会来的。
Suppose he doesn’t agree，what shall we do?假如他不同意，那怎么办?
I shall do as I please. 我高兴怎么做就怎么做。
He will continue the work no matter what happens. 不管发生什么情况他都要继续这项工作。
2. 在the more…the more …(越……越……) 句型中,前者通常用一般现在时代替一般将来时，因为前者相当于条件状语从句。如：
The harder you study, the better results you will get. 你学习越努力，成绩就会越好。
3. 在make sure (certain) , see to it, mind, care, matter后的宾语从句的谓语动词用一般现在时代替一般将来时。如：
See to it that you are not late again. 注意别再迟到了(from www.hxen.com)。
4. 表示按计划或时间表将要发生的动作，通常有表示将来的时间状语。如：
The plane takes off at 11:30 and arrives in Shanghai at l:20. 飞机十一点半起飞，一点二十分抵达上海。
注：只限于少数动词能这样用，如 begin, start, , end, finish, stop, go, come, leave, sail, arrive, return, close, open 等。
Present Perfect - Use
The Present Perfect is not easy to understand for ESL learners. It is a combination of past and present. An action in the past has something to do with the present.
1) Result of an action in the past is important in the present (It is not important when this action happened. When we use a specific time in the past - e.g. yesterday - then we use the Simple Past.)
I have cleaned my room. (It is clean now.)
Has Peggy ever been to
2) Recently completed actions
He has just played handball. (It is over now.)
3) Actions beginning in the past and still continuing - mostly with since (point of time) or for (period of time)
We have lived in
4) together with lately, recently, yet
I have been to
He has not written the e-mail yet. (He has not done it.)
一、现在完成时由“have/has+过去分词”构成，主要有两个含义
① 表示动作发生在过去，但与现在的情况有联系，有时无时间状语，有时和一些表示不确定的过去时间状语连用，如：many times，just，yet，ever，never，just，already，before，so far, by now等连用。
② 表示从过去某一时间开始一直延续到现在并还可能继续延续下去的动作，用于延续性动词，且句中常带有表示一段时间的时间状语，如：since，for two months, in the last, so far等
二 、现在完成时和一般过去时都能表示过去发生过的动作，但现在完成时表示过去动作对现在的影响，并且表示这一动作已完成或还可能继续下去；而一般过去时与现在的情况没有联系，仅表示过去的动作，且这一动作到说话时已终止。因此现在完成时不能与表示明确的过去时间如when，in1949，yesterday，last week等的状语连用，并且用when或where对这些时间和地点状语提问时，一般只用一般过去时。
三、在“it is first/second...time that...。”或在“it/this/that is the +最高级+名词+that...。”结构中，that从句中的动词常用现在完成时；在“it + be ...+since从句”这一结构中，be可用一般现在时或现在完成时，since从句一般用过去时
Past Perfect - Use
1) Together with the Simple Past
When two past actions are combined - the first action, which was completed before the second one began, is put into Past Perfect.
Mary had read the book before she watched a film.
After Amy had gone home it started to rain.
2) the past equivalent of the Present Perfect
He had played hockey.
一般过去时表示过去某个时间里发生的动作或状态；过去习惯性、经常性的动作、行为；过去主语所具备的能力和性格。基本结构：主语+动词过去式+其他；否定形式①was/were+not;②在行为动词前加didn't，同时还原行为动词；一般疑问句Did+主语+do+其他。
时间状语
Ago:（two hours ago（一段时间+ago）, yesterday, the day before yesterday, last week, last(year, night, month…), 具体时间, just now, at the age of , one day, long ago, once upon a time(很久以前), and so on.（填时间如：two days）+ago
Did you have a party the other day？
Mrs. Peter always carried an umbrella.
I never drank wine.
I used to take a walk in the morning.
I didn’t know you were in
Simple Future has two different forms in English: "will" and "be going to." Although the two forms can sometimes be used interchangeably, they often express two very different meanings. These different meanings might seem too abstract at first, but with time and practice, the differences will become clear. Both "will" and "be going to" refer to a specific time in the future.
FORM Will
[will + verb]
Examples:
You will help him later.
Will you help him later?
You will not help him later.
FORM Be Going To
[am/is/are + going to + verb]
Examples:
You are going to meet Jane tonight.
Are you going to meet Jane tonight?
You are not going to meet Jane tonight.
一般将来时表示将来某一时刻的动作或状态，或将来某一段时间内经常的动作或状态。常常和表示将来的时间状语连用。如：tomorrow（明天）， next week（下周）， from now on（从现在开始）；in the future（将来）等。 一般将来时由助动词shall（第一人称），will（第二、三人称） 动词原形构成。美国英语则不管什么人称，一律用will。
基本句型
肯定句：I/We shall/will go. You/He/She/They Will go.
否定句：I/We shall/will not go. You/He/She/They Will not go.
疑问句：Shall I/we go? Will you/he/she/they go?
简略回答：（肯）Yes,主语 shall/will (否) No,主语 shall/will not
特殊疑问句：一般将来时的特殊疑问句是将疑问词放在句首，后接一般疑问句（就主语提问时，以疑问词who开头的疑问词除外）
----- why will you be here on Sunday?（周日你为什么将要在这儿？）
-----I will have a meeting on Sunday（我将要在周日举行一个聚会）（对特殊疑问句要进行具体回答）
Modal auxiliary expressions are words or phrases that change the meaning of a verb.
Modals are used directly before the verb in a sentence.
Always use the base form of the verb following a modal auxiliary.
情态助动词
can/could
may/might
shall/should
will/would
must（可以/能够/将要/应该/必须） Modals express permission, ability, obligation, or prediction:情态助动词表示许可、能力，或者预测。
You can have a sweet if you like（想要的话你可以来一颗糖）
He may arrive early（他可能早到）
Paul will be a footballer some day （保罗有朝一日会成为足球运动员）
I really should leave now（我真的该走了）
Infinitives are defined as to + base form of the verb. They have several functions.
To know me is to love me.
To live in
I wanted to tell you how much I appreciated your gift.
He hesitated to ask the embarrassing question.
You must take this medicine (in order) to get well.
I went to the bank to cash a check.
Infinitives can sometimes take objects of their own.
We hope to find the person who did this.
I was asked to make a dessert for the potluck dinner.
“动词不定式”，是一种非限定动词，由不定式符号to+动词原形构成。不定式具有动词的特征，同时也有名词、形容词和副词的特征。 动词不定式是一种非限定性动词，由to＋动词原形构成，但它还是属于动词，所以它本身可以带宾语和状语。动词不定式在句中可以作主语、宾语、表语、定语和状语，还可用在复合结构中，而且有完成式、进行式、完成进行式和否定形式。动词不定式的被动形式除了一般形式外还有其完成式和进行式。
1) 现在时：一般现在时表示的动词，有时与谓语动词表示的动作同时发生，有时发生在谓语动词的动作之后。
He seems to know this.
I hope to see you again. = I hope that I'll see you again. 我希望再见到你。
2) 完成时：表示的动作发生在谓语动词表示的动作之前。
I'm sorry to have given you so much trouble. 很抱歉给你添了这么多麻烦。
He seems to have caught a cold. 他似乎感冒了。
3) 进行时：表示动作正在进行，与谓语动词表示的动作同时发生。 He seems to be eating something.他似乎吃一些。
4) 完成进行时：She is known to have been wreaking on the problem for many years.
There are some rules to help you make comparisons in English.
For example: small – smaller; big – bigger; nice – nicer.
For example: lucky – luckier; happy – happier.
For example: handsome – more handsome; beautiful – more beautiful and so on.
"She's younger than me."
"This exercise is more difficult than the last one."
For example: She's as tall as her brother" or "It's as nice today as it was yesterday."
For example: "This programme is less interesting than I thought" or "This programme is not as interesting as I thought."
For example: good – better; bad – worse; far – further.
比较级在英语中通常用下列方式表示的词：在形容词或副词前加more(如 more natural, more clearly )或加后缀 -er(newer, sooner )。典型的是指形容词或副词所表示的质、量或关系的增加。英语句子中，将比较两个主体的方法叫做“比较句型”。其中，像“A比B更……”的表达方式称为比较级。组成句子的方式是将形容词或副词变化成比较级的形态。
特殊句型
She felt herself becoming more and more nervous.
As the winter is drawing near, it's getting colder and colder.
Jane is the taller of the two children in our family.
The more magazines you sell, the more money you will get.
— Wait until we get a satisfactory reply, will you?
— I couldn't agree more. The idea sounds great to me.
How beautifully she sings！I have never heard a better voice.
The dining hall is three times as large as that one.
The dining hall is three times larger than that one.
The dining hall is three times the size of that one.
In grammar, a conjunction (abbreviated conj or conj) is a part of speech that connects two words, sentences, phrases or clauses together. Conjunctions have three basic forms:
Single Word
For example: and, but, because, although
Compound (often ending with as or that)
For example: provided that, as long as, in order that
Correlative (surrounding an adverb or adjective)
For example: so...that
（1）表示增加的过渡词：also，and，and then，too，in addition，further more，more over，again，on top of that，another，firstsecondthird等。
（2）表示时间顺序的过渡词：now，then，before，after，afterwards，earlier，later，immediately，soon，next，in a few days，gradually，suddenly，finally等。
（3）表示空间顺序的过渡词：near（to），far（from），in front of，behind，beside，beyond，above，below，to the right/ left，around，outside等。
（4）表示比较的过渡词：in the same way，just like，just as等。
（5）表示对照的过渡词：but，still，yet，however，on the other hand，on the contrary，in spite of，even though等。
（6）表示结 果 和 原 因 的 过 渡 词：because，since，so，as a result，therefore，then，thus，otherwise等。
（7）表示目的的过渡词：for this reason，for this purpose，so that等。
（8）表示强调的过渡词：in fact，indeed，surely，necessarily，certainly，without any doubt，truly，to repeat，above all，most important等。
（9）表示解释说明的过渡词：for example，in fact，in this case，for actually， for instance等。
（10）表示总结的过渡词：in a word, above all, all in all, finally，at last，in conclusion，as I have shown，in another word，in brief，in short，in general，on the whole，as has been stated等
When using indirect or reported speech, the form changes. Usually indirect speech is introduced by the verb said, as in I said, Bill said, or they said. Using the verb say in this tense, indicates that something was said in the past. In these cases, the main verb in the reported sentence is put in the past. If the main verb is already in a past tense, then the tense changes to another past tense; it can almost be seen as moving even further into the past.
一. 人称代词要随人而变
直接引语变间接引语时，人称代词有变化，要随说话者、听话者、转述者和其他人的关系进行相应变化。注意两种情形：
He said, “I am going to see her this afternoon.” →
He said that he was going to see her that afternoon. （引语中的I是说话者he，引语的her既不是说话者也不是转述者，故her不变）
He said to my sister，“You didn’t go there.” →
He told my sister that she hadn’t gone there. （引语中的you是听话者my sister，故you变为she）
二. 谓语动语的时态要推向过去
由于转述的是他人先前说过的话，因此变为间接引语时，时态应推向过去相应时态。基本变化规律是：一般现在时→一般过去时，一般将来时→过去将来时，现在进行时→过去进行时，现在完成时→过去完成时，一般过去时/过去完成时→过去完成时。如：
My friend told me，“I will visit the Great Wall next week.” →
My friend told me that he would visit the Great Wall the next week.
三．特殊词语有固定变化
一些指示代词、动词，以及一些表示时间、地点状语的名词和副词，都有固定的变化。比如：
She said, “I will come here again tomorrow.” →
She said that she would go there again the next day.
My friend said，“I arrived here yesterday morning. →
My friend said that he had arrived there the morning before.
A relative clause is a subordinate clause that modifies a noun phrase, most commonly a noun. For example, the phrase "the man who wasn't there" contains the noun man, which is modified by the relative clause who wasn't there. A relative clause can also modify a pronoun, as in "he to whom I have written", or a noun phrase which already contains a modifier, as in "the black panther in the tree, which is about to pounce". The complete phrase (modified noun phrase plus modifying relative clause) is also a noun phrase.
定语从句又称为关系从句，分为限定性和非限定性两种，不仅仅可表达对中心词的限定和修饰关系，在不同语境中可表示不同语义关系。
限制性定语从句
关系代词：在句中作主语、宾语或定语
非限制性定语从句
Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了，他曾经是我的老师。
My house, which I bought last year, has got a lovely garden. 我去年买的的那幢房子带着个漂亮的花园。
This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。
He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这使我心烦。
Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。
Passive voice is a grammatical voice common in many of the world's languages. Passive is used in a clause whose subject expresses the theme or patient of the main verb. That is, the subject undergoes an action or has its state changed. A sentence whose theme is marked as grammatical subject is called a passive sentence. In contrast, a sentence in which the subject has the agent role is called an active sentence, and its verb is expressed in active voice. Many languages have both an active and a passive voice; this allows for greater flexibility in sentence construction, as either the semantic agent or patient may take the syntactic role of subject.
在英语中的被动语态使用得比汉语要多，要普遍。 一般说来，当强调动作承受者，不必说出执行者或含糊不清的执行者时，多用被动语态。需要注意的是，许多地方与汉语不同。注意：哪些汉语中没有"被……"的意思，英语却应该用被动态。还要注意，英语的被动态往往由"by"引出，而有用介词"by"的短语往往又不是被动语态，而是主系表结构。还有些特殊现象，如：known to man(人类......所知)，on foot步行(美国人有时用by foot)，in carriage(乘四轮马车)等等。
A person who is truly honest is called a straight arrow. 直言不讳的人才是真正诚实的人。
A note was passed up to the speaker. 有人给讲演者递上来一张纸条。
John was elected president of the class instead of Harry. 乔治被选为班长而代替了亨利。
In grammar, the subjunctive mood (abbreviated sjv or sbjv) is a verb mood typically used in subordinate clauses to express various states of irreality such as wish, emotion, possibility, judgment, opinion, necessity, or action that has not yet occurred.
语气是一种动词形式，用以表示说话者的意图或态度。虚拟语气表示说话者的主观愿望、假想和建议等，所说的话有的与现在事实相反，或与过去事实相反，或与将来事实相反或与将来事实可能相反。所以虚拟语气总是与假设条件句用在一起。除了if条件句外，还有几种常用的条件句，短语也可表示条件。此外，上下文也能创造虚拟的语言环境。但有时条件从句与结果主句可能发生时间不一致，有时虚拟语气会出现倒装情况。除了与条件句在一起使用的主句用虚拟语气外，有些宾语从句或表语从句也有用虚拟语气的情况。
虚拟(条件)语气中，主句与从句中谓语动词的形式可分为下面四类
1.与现在事实相反
动词的过去式(be用were而不用was)
would(第一人称可用should)
+动词原形
If I knew his telephone number, I would tell you. 如果我知道他的电话号码，我就会告诉你。
2. 与过去事实相反
had+ -ED分词
would(第一人称可用should)
+have + -ED分词
If he had taken my advice, he would not have made such a mistake. 如果他听我的劝告的话，就不会犯这样的错误了。
3. 与将来事实相反
were to + 动词原形
would(第一人称可用should)
+动词原形
If there were no air or water, there would be no living things on the earth. 如果没有水和空气，地球上就不会有生物。(事实：地球上既有空气也有水)
4. 与将来事实可能相反
should + 动词原形
would(第一人称可用should)
+动词原形
Should he agree to go there, we would send him there.
要是他答应去的话，我们就派他去。