Declarative Sentence and Word Order

Declarative sentences in English consist of a subject and predicate.

The verb in the predicate is conjugated appropriately for the subject and in a specific tense:

subject +  predicate

• Mary  speaks English.

Let’s look at some examples that illustrate this. Declarative sentences can have a singular or plural noun as their subject and can be followed by a verb in any tense and by the complement of the sentence.

John repairs the car.

The boys ran into the forest.

Other declarative sentences use a pronoun as their subject, and again the tense of the sentence can vary. 

She has never been to England.  singular-pronoun subject, present-perfect-tense verb

We shall visit them soon. plural-pronoun subject, future-tense verb

Since English verbs can show an incomplete action or one in progress (he is going) or a completed or habitual action (he goes), when changing tenses, you have to conform to the type of action of the verb. For example:

he is going, he was going, he has been going
he goes, he went, he has gone

The conjugation of English verbs is, with few exceptions, a relatively simple matter, but using the proper tenses of verbs is something else. It is particularly important to understand the tense differences between verbs that describe an action in progress and verbs that describe a completed or habitual action.

Incomplete actions

Let’s look at some sentences that illustrate the meaning of incomplete actions—or ones in progress—in the present, past, and future tenses. Note that in some cases, it is an interruption of some kind that causes the action to be incomplete. (To the right of the examples are italicized clarifications that will help you fully understand the example sentences.)

Present tense

He is washing the car. (He has not finished. The car still has some dirty spots.)

We are building a tree house. (The tree house is not yet finished.)

Past tense

I was sleeping when he called. (I didn’t finish my nap. His call interrupted my sleep.)

The men were working in the mine, but suddenly quit.   (The work in the mine is unfinished, because the men quit.)

Future tense

He will be playing in a rock band. (There is no apparent end to his job in the band.)

Sarah will be needing more money. (There is no apparent end to Sarah’s need for money.)

Completed actions

Compare those examples with the following sentences that illustrate verbs that describe completed or habitual actions:

Present tense

He washes the car every Sunday. (His habit is to wash the car on Sunday.)

They live in the capital. (Their regular place of residence is the capital.)

Past tense

The puppy slept with me every night. (The puppy’s habit was to sleep with me.)

I worked in Mexico for five years. (My work for five years was in Mexico. I work  elsewhere now.)

Future tense

He will play a hymn for us on the piano. (He is going to play the hymn just once.)

Uncle Bill will arrive today. (Uncle Bill will arrive today only once.)

The perfect tenses conform to the same kinds of meanings. For example:

Incomplete action or one in progress

He has been washing the car for three hours.

I had been sleeping in the den.

The men will have been working on it for twenty-four hours by tomorrow.

Completed or habitual action

They have lived here since June.

The pup had never slept so long before.

Uncle Bill will have arrived home by the time we get there.

Reference: Ed Swick in Practice Makes Perfect