Grammar

Grammar is the information that is added to a sentence, not by the words, but by how the words are put together.

Some Example Sentences
Firstly, think about this: How are the meanings of these sentences different: These sentences are made of mostly the same words: John, kiss, and Mary.
 * John kisses Mary.
 * John kissed Mary.
 * John is kissing Mary.
 * John has been kissing Mary.
 * John has kissed Mary.
 * John will kiss Mary.
 * Mary will kiss John.

In all the sentences, the words "John" and "Mary" always belong to the noun word class, and "kiss" always belongs to the verb word class; but the meaning of each sentence is different. Why?

The reason these sentences have different meanings is because of information added by grammar. Grammar adds information like:


 * When is/did/will the action take place? (TENSE)
 * Is the action still happening? (ASPECT)
 * Who is doing the action? And who is receiving the action? (CASE)
 * How many people/things are doing the action? (NUMBER)
 * Do you know who is doing the action? (DEFINITENESS)

Grammar in English
Every sentence has some grammatic information, because English needs some grammatical information to be included in every sentences. For example, every English sentence needs information about the grammatical categories: CASE, DEFINITENESS, MOOD, NUMBER, and TENSE.

On the other hand, some grammatical information is optional. So, for example, most sentences will not contain information related to the grammatical categories: ASPECT and NOUN CLASS.

How is Grammatical Information Added to a Sentence?
In English, grammar information is usually added:


 * by adding special "function words" (has, had, had been, will) to the sentence, OR


 * by adding suffixes (-es, -ed, -ing) to words.

See the article on grammatical categories to learn more about what types of information are added to a sentence by different grammatical categories.