It is a combination of words that makes a statement, asks a question, expresses a wish or a command, or is merely exclamatory.

a) Assertive, making a statement.
He likes all kinds of music. (affirmative)
He does not like all kinds of music. (negative)

b) Interrogative, asking a question.
When will you come again?

c) Optative, expressing a wish.
May you never hav a similar misfortune!

d) Imperative, expressing a command (or giving advice).
Come here. Be careful.

e) Exclamatory, expressing some emotion.
What a fool I have been!

2) A sentence generally consists of at least two parts - The subject and the predicate.

The word (or words) denoting the person or thing about which something is said is called the subject of the sentence.
The word (or words) which says something about the person or thing denoted by the subject is called the predicate of the sentence.

a) Snow is falling.
b) My friends have left London.

In a), the subject is "snow" and the predicate is "is falling"

In b), the subject is "my friends" and the predicate is "have left London"

3) If a name is given to some person or thing, such as Henry, boy, iron, crowd, kindness, this word is called a noun.

4) It is often not convenient to have to repeat a noun and so we use a subtitute word for it, which is called a pronoun.

My sister was late because she (my sister) was detained.

5) Sometimes we have no suitable noun to express some particular action or state and then we form a noun from a verb, which may be either a gerund or an infinitive. Gerunds and noun infinitives are partly nouns and partly verbs. As they do the work of nouns, they, as well as the pronoun, may be called noun equivalents.

Singing is her only pastime. (Gerund)
To sing is very healthy (Noun infinitive)

6) If we wish to describe or determine a person or thing named by its pronoun, we call the word used for this purpose an adjective.

That young man has slender hands.

7) The word that states that a person or thing named in the subject is, does, or suffers something is called a Finite verb, i.e. It has a subject (given or understood) with which it agrees in Number (singular or plural) and person (first, second, or third)

She always comes late. They come early.

In the first example "comes" is singular, 3rd person, because its subject is singular, 3rd person, because its subject is plural, 3rd person.

8) Some parts of a verb cannot be used as the predicate, and these are called "Parts of a verb not finite" There are three such parts:

a) The infinitive, b) the participle, (c) the gerund.

Whereas the gerund may be partly an adjective and partly a verb.

The faded flowers were thrown away. The singing boy is my brother.

Here, although, "faded" and "singing" are formed from verbs, they describe the nouns "flowers" and "boy" respectively.

A participle may be purely verbal in function, as:

The rose has faded. The boy is singing.-

9) If a verb expresses an action that directly affects some thing (other than the subject) named in the sentence, it is said to be transitive. A verb that is transitive has a passive form, which shows that the thing denoted by the subject suffers the action expressed by its verb. If the subject does the action expressed by its verb, the latter is said to be in the "active voice". There are, consequently, two voices, the active voice and the passive voice.

He made a mistake. A mistake was made by him.

In both of these sentences the verb is transitive. In the first example, the action expressed by the verb "made" affects the word "mistake", which is called the object of the transitive verb "made". In the second example, the subject "mistake" suffers the action expressed by the verb "was made".

10) If the action of a verb does not affect some thing (other than the subject) named in the sentence, it is said to be intransitive. An intransitive verb has no passive form.

My sister skates.

Here "skates" is intransitive as the action stops with the doer and does not affect any other person or thing.

11) If a transitive verb together with its object and subject and an intransitive verb together with its subject make complete sense, they are called: verbs of complete predication, as:

She speaks french (Transitive verb of complete predication)

Birds fly. (Intransitive verb of complete predication)

Sometimes a transitive verb and an intransitive verb do not make complete sense under the above conditions and they require some word or words to complete the sense. They are then called "verbs of incomplete predication"

She has set the bird free. She seems tired.

12. The mood of a verb is the form assumed by a verb (either by inflexion or with the help another verb called an auxiliary verb) to show the manner or mode of the action or the state denoted by the verb.

There are three principal moods:

(1) The indicative, or mood of fact. He will come tomorrow.
(2) The imperative, or mood of command or advice. - Speak louder.
(3) The subjunctive, or mood of supposition.- If I were you, I should be happy.

In (I) "will come" states a fact, so that this verb is in the indicative mood. In (2) "speak" expresses a command, and it is in the imperative mood. In (3) "were" and "should" "be" are in the subjunctive mood, because they express a condition merely thought of, but not stated as even a possible fact.

13) The tense of a verb is the form assumed by it (either by inflexion or with the help of auxiliary verbs) to show the time or the degree of completeness of the action or state denoted by the verb.

My brother is working.-- I have finished my work.

"Is working" is the present continuous tense. It shows that the action of working is still continuing. "have finished" is the present perfect tense. It shows that the action of finishing has been completed.

14) An auxiliary verb is a verb that helps to form a tense or a mood of some other verb.

They have been singing an hour already. May you always be happy!

"Have" and "been" are both auxiliary verbs as they help to form the present perfect continuous tense of the verb "to sing" "May" is an auxiliary verb as it helps to form the subjunctive of wish of the verb "be". The verbs that are jelped by these auxiliary verbs are called "principal verbs"

15) The adjectives "a" "an" and "the" are generally called "articles"

"A" and "an"are indefinite articles, and "the" is the definite article"