Sentences
A sentence is a unit of language that typically contains a subject and a verb and expresses a complete thought. Follow the lesson to find out how it works.
What Are Sentences?
Sentences: Types Based on Mood
Sentences are mainly categorized into four moods as follows:
Declarative Sentences
Declarative sentences give information about something. They have a subject and a predicate which is made of a verb and sometimes a subject complement or an object complement. Here are the examples.
My mother used to have long straight hair.
His father isn't rational enough to bear this.
Declarative sentences are further divided into two groups:
- negative declarative sentences
- affirmative declarative sentences
Affirmative sentences have positive verbs. We use negation rules to form negative sentences. Check out the examples.
You
We
Interrogative Sentences
We use the interrogative mood to ask questions or to ask for information about something. Usually, interrogative sentences are inverted. Here are the examples.
What was your name again?
Were you at the party last night?
Interrogative sentences are categorized into two groups:
Wh-questions start with an interrogative-word and yes/no questions start with an auxiliary verb. Check the examples.
Imperative Sentences
Imperative sentences are used to give orders. They are usually made of only one word which is actually the imperative verb. Here are some examples:
Sit down!
Have fun!
English Imperative sentences are also of two types:
- imperative sentence using only one verb
- imperative sentence using a subject and a verb
The subject of an imperative sentence is the pronoun 'you' that is usually omitted because it is implied in the meaning of the imperative verb. For example:
You
Speak!
Imperative Verbs vs. 'Should' and 'Must'
Should and must are not imperative verbs. Imperative verbs can be used without subjects. However, you can never use modal verbs on their own as an imperative verb. So, If you can omit the subject without harming the formation of the sentence, then the verb is an imperative verb.
In this example, start is an imperative verb.
In this example the verb 'must' cannot be used without a subject so it isn't an imperative verb.
Negative Imperatives
Since imperative verbs are all main verbs, to form negative imperatives all you have to do is add don't to the beginning of the imperative sentence. For example:
Exclamatory Sentences
Punctuation Marks
Every type of sentence is followed by a particular punctuation mark. You can see the punctuations used for each sentence type on the following list:
- Period: declarative sentences (.)
- Question mark: interrogative sentences (?)
- Exclamation mark: exclamatory and imperative sentences (!)
Sentences: Types Based on Structure
Based on their structure, sentences are categorized into four groups:
Simple Sentences
Simple sentences consist of a subject as the doer of activity and a predicate which represents the action. Simple sentences are not followed by any other dependent or subordinate clauses. For example:
Compound Sentences
Compound sentences are two independent sentences that are joined together using linking words or conjunctions, and semicolons. Here are the examples:
This is too expensive,
I want to gain weight,
Complex Sentences
Complex sentences are formed from an independent clause and at least one dependent clause linked to the independent clause. Here are the examples.
I moved in
You will pass
Compound-Complex Sentences
Compound-complex sentences combine compound sentences with complex sentences. A compound-complex sentence has at least two independent clauses and one dependent clause. Here are the examples:
He cried
I am beautiful
Review
Sentences are made from different words. Based on their mood they are categorized into four groups:
- declarative
- interrogatory
- imperative
- exclamatory
Based on their structure, they are categorized into four groups as well.
- simple sentences
- compound sentences
- complex sentences
- compound-complex sentences