There are four sentence types in English: Declarative, Imperative, Interrogative and Exclamatory.
Declarative: Tom'll come to the meeting tomorrow.
Imperative: Turn to page 232 in your science book.
Interrogative: Where do you live?
Exclamatory: That's awesome!
A declarative sentence "declares" or states a fact, arrangement or opinion. Declarative sentences can be either positive or negative. A declarative sentences ends with a period (.).
I'll meet you at the train station.
The sun rises in the East.
He doesn't get up early.
The imperative form instructs (or sometimes requests). The imperative takes no subject as 'you' is the implied subject. The imperative form ends with either a period (.) or an exclamation point (!).
Open the door.
Finish your homework.
Pick up that mess.
The interrogative asks a question. In the interrogative form the auxiliary verb precedes the subject which is then followed by the main verb (i.e., Are you coming ....?). The interrogative form ends with a question mark (?).
疑问句就是提出问题的句式。疑问句中，助动词位于主语前面，而主语后则跟着主动词（例如：Are you coming..?）。疑问句以问号结尾。
How long have you lived in France?
When does the bus leave?
Do you enjoy listening to classical music?
The exclamatory form emphasizes a statement (either declarative or imperative) with an exclamation point (!).
That sounds fantastic!
I can't believe you said that!
Writing in English begins with the sentence. Sentences are then combined into paragraphs. Finally, paragraphs are used to write longer structures such as essays, business reports, etc.
The first sentence structure is the most common:
Simple sentences contain no conjunction (i.e., and, but, or, etc.).
简单句中没有连接词（如and, but, or等）
Frank ate his dinner quickly.
Peter and Sue visited the museum last Saturday.
Are you coming to the party?
Compound sentences contain two statements that are connected by a conjunction (i.e., and, but, or, etc.).
复合句由两个陈述构成，这两个陈述由连接词（如and, but or等）连在一起。
Practice writing compound sentences with this compound sentence writing exercise.
I wanted to come, but it was late.
The company had an excellent year, so they gave everyone a bonus.
I went shopping, and my wife went to her classes.
Complex sentences contain a dependent clause and at least one independent clause. The two clauses are connected by a subordinator (i.e, which, who, although, despite, if, since, etc.).
主从复合句中含有一个独立的从句，且至少有一个。两个从句由一个从属连词（如which, who, although, despite, if, since等）连接起来。
My daughter, who was late for class, arrived shortly after the bell rang.
That's the man who bought our house.
Although it was difficult, the class passed the test with excellent marks.
4.Compound - Complex Sentences
Compound - complex sentences contain at least one dependent clause and more than one independent clause. The clauses are connected by both conjunctions (i.e., but, so, and, etc.) and subordinators (i.e., who, because, although, etc.)
并列复合句和主从复合句都含有一个或以上的独立的从句。从句由连词（如but, so, and等）和从属连词（如who, because, although等）
John, who briefly visited last month, won the prize, and he took a short vacation.
Jack forgot his friend's birthday, so he sent him a card when he finally remembered.
The report which Tom compiled was presented to the board, but it was rejected because it was too complex.