Simple Future or Future Indefinite Tense

Affirmative
I will/shall write.
He will/shall write.
They will/shall write.

Negative
I will/shall not write.
He will/shall not write.
They will/shall not write.

Interrogative
Will/shall I write?
Will/shall he write?
Will/shall they write?

The Past Perfect Tense

Affirmative
I had worked.
She had worked.
They/you/we had worked.

Negative
I had not worked.
She had not worked.
They/you/we had not worked.

Interrogative
Had I worked?
Had she worked?
Had they/you/we worked?

The Simple Past or Past Indefinite Tense

Affirmative

I wrote.
She wrote.
They/you/we wrote.

Negative

I didn’t write.
She didn’t write.
They/you/we didn’t write.

Interrogative

Did I write?
Did she write?
Did they/you/we write?

Present Perfect Tense

Form
Affirmative
I have written.
He has written.
They/you/we have written.

Negative
I have not written.
She has not written.
They/you/we have not written.

Interrogative
Have I written?
Has he written?
Have they/you/we written?

The present perfect tense is used to talk about an action just completed.
Read the sentences given below.

The present indefinite or the simple present

Form:
Affirmative

I work.
She works.
They/you work.

Negative

I don’t work.
She doesn’t work.
They/you don’t work.

Interrogative

Do I work?
Does she work?
Do they/you work?

The simple present tense has several uses.

We have seen that the past perfect tense is used to talk about a completed past action. Note that when two past actions have to be mentioned, the past perfect is used for the earlier of the two, and the simple past for the later.

The tense of a verb shows not only the time of the action but also whether it is complete or not. There are three tenses in English:

1.    The Present Tense
2.    The Past Tense
3.    The Future Tense

The Present Tense refers to the present time. It has four forms:

Incorrect: He has stole my pen.
Correct: He has stolen my pen.
Incorrect: John has often beat me at tennis.
Correct: John has often beaten me at tennis.

Reason
After the auxiliaries has, have and had, we use the past participle form of the verb.

Incorrect: He told her that he will come.
Correct: He told her that he would come.

Reason
When the principal verb is in the past tense the verb in the subordinate clause should also be in the past tense. When the principal verb is in the present tense, the verb in the subordinate clause can be in any tense.

Again and again: frequently, repeatedly

We shouldn’t commit the same mistake again and again.

Now and again: once in a while, at times, from time to time, occasionally

She writes now and again.
I visit my grandparents now and again.

All in all: Everything being taken into account