Understanding Sentences

1

All sentences must have a subject and a verb. Some sentences can be very short. For example, "I ate" is a complete sentence. Why? It has a subject and a verb. Other sentences can be very, very long.

People often make mistakes when making English sentences. One common mistake is the run-on sentence. Look this sentence:

I went to the park I saw my friend.

It's a run-on sentence. A run-on sentence is a combination of two sentences that either needs punctuation or a conjunction（符号或连词）. Here's a complete sentence:

I went to the park, and I saw my friend.

All sentences need to have subject-verb agreement. It means that if the subject is singular, the verb must be singular. And if the subject is plural, the verb must be plural. Look at this sentence:

Jason like to play computer games.

It's a wrong sentence. Why? It doesn't have subject-verb agreement. Here is the correct complete sentence:

Jason likes to play computer games.

So watch out for run-on sentences, and always make sure your subjects and verbs agree. Then you'll be making a lot of complete sentences.

2

Writing in English is not easy. There are many grammar rules. So you have to be very careful. Tow common mistakes are sentence fragment and comma splices.

A sentence fragment is an incomplete sentence. A sentence must always have a subject and a verb. Look at the following sentence fragments:

attends the school
My farther, who is a doctor

Neither of these is complete. The first fragment needs a subject. The second fragment needs a verb. Make them complete sentences like this:"Jane attends the school." "My father, who is a doctor, is home now."

Comma splices are also common mistakes. These are sentences that use a comma to connect to independent clause. Look at the following comma splices:

My brother studies hard, he's a good student.
I'm sorry, it was an accident.

Neither of these is correct. The first sentence either needs a period or the word because:"My brother studies hard because he's a good student." The second sentence needs a period, not a comma:"I'm sorry. It was an accident."

了解五大基本句型

Subject + Verb
The bell rings.
Subject + Link. Verb + Predicative（表语）
Tom is a student.
Subject + Verb + Object
Tom has read the book.
Subject + Verb + Indirect Object + Direct Object
My girlfriend bought me a nice wallet.
Subject + Verb + Object + Complement（补充）
The school makes him very famous.