ESET Principles

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Essential Structure of English Tenses

(ESET Principles)


  1. Prime verb is influenced by the tense, subject and type of a sentence. Rest of the verbs and auxiliary verbs only and necessarily follow the prime verb.
  2. Present and past tenses are shown by 1st* and 2nd* forms respectively whereas future is indicated by the presence of will or shall as the prime verb.
  3. A form of be (auxiliary verb) followed by 3rd* form of verb is a passivizer.

* 1st, 2nd, 3rd and 4th forms of verb represent infinitive, past (preterite), past participle and present participle respectively.


The ESET Principles and their terms are briefly explained below.

1. Prime Verb

The very first verb or auxiliary verb in a sentence is prime verb. For instance, the underlined words are prime verbs of the following sentences:

  1. He talked to me yesterday.
  2. May I come in?
  3. I am thinking about something new.
  4. Ali will be in contact with you soon.

2. Following of Verbs

The conjugation of an English verb occurring after another verb or auxiliary verb is set by the one that precedes it. The verb cannot take a form independently. It must follow its precedent. Following is a table (not exhaustive, by any means) that illustrates what follows what:

No. Auxiliary Verb Indicates Followed by
1 be* continuity 4th form
2 be* passivization 3rd form
3 have* completion 3rd form
4 will intention (future) 1st form
5 shall urge (future) 1st form
6 may probability 1st form
7 can possibility 1st form
8 must obligation 1st form
9 let* suggestion 1st form
10 do* activity 1st form
11 (auxiliary verb) to various 1st form
12 keep* repetition (similar to be) 4th form
13 get* execution (similar to have) 3rd form

* These auxiliary verbs act as both normal and auxiliary verbs.

3. Influence of Subject

The subject of a sentence sometimes forces the prime verb to take a specific shape that is actually just a permutation of the original conjugation. Look at the following sentence for example:

Maria has passed all the exams.

Here, has is actually the same as have. It is just a permutation of have that is used with singular subjects.

Let us see some more examples:

  1. I am working on a new project.
  2. They are done with their work.
  3. She looks great.
  4. Dawud was not interested in computer science.
  5. The Greeks were an intellectual nation.

The first two underlined words are permutations of the 1st form of be, the third one is that of the 1st form of look and the last two are variations of the 2nd form of be.

Given below is a chart to illustrate some general permutations of the auxiliary verbs:

No. Auxiliary Verb 1st Form 2nd Form 3rd Form 4th Form
1 have have, has had had having
2 be be, is, am, are was, were been being
3 can can could --- ---
4 may may might --- ---
5 will will would --- ---
6 shall shall should --- ---
7 must must --- --- ---
8 let let, lets let let letting
9 do do, does did done doing

As for the normal verbs, they have two permutations in their 1st forms only:

  1. The regular 1st form with first person and plural subject, e.g., put, come, go, etc.
  2. The 1st form with s or es ending for singular subjects, e.g., puts, comes, goes, etc.

Among the above mentioned permutations, has, is and 1st form of verb+s/es are associated with singular subject, Have, are and 1st form of verb (without s/es) are for plural subject and am and have are followed by first person. That is all we mean by influence of subject on prime verb.

4. Type of Sentence

Type indicates whether the sentence is affirmative (positive), negative, interrogative or imperative, etc. It is also related to the prime verb in the following manner:

  • Affirmative: The prime verb occurs just after the subject.
  • Negative: A not is appended after the prime verb.
  • Interrogative: The prime verb occupies a place before the subject.
  • Imperative: The prime verb replaces the subject.

Here are a few examples:

  1. Rachel was thinking about the new proposal. (Affirmative)
  2. I have not taken a decision yet. (Negative)
  3. Can you give me a little favor? (Interrogative)
  4. Show me something new. (Imperative)
  5. Let us walk together. (Imperative)

The underlined words in above sentence are prime verbs.

It must be noted here that let, when occurring at the beginning of a sentence, converts the expression into something like a humble imperative. It is not a command in the strict sense of the word, yet it belongs to the same category; hence its position in the sentence.

5. The Case of Do

The simplest expression of an action that does not imply continuity, completion, possibility, etc., is indefinite. Sentence that fall under this category and belong to present or past tense are bound to use the actual verb as their prime verb. For instance:

  • He reads a lot.
  • You looked your best yesterday.

In either of the above sentence, the verb itself is the prime verb.

In such cases, we introduce an appropriate form of do (Principle No. 2 & Explanation No. 2 & 3) as the prime verb in negative or affirmative sentences. Hence, the negative and interrogative types of the above sentences are:

  • He does not read a lot.
  • Does he read a lot?
  • You did not look your best yesterday.
  • Did you look your best yesterday?

6. Passivization

Passive voice in English is necessarily associated with some form of be followed by 3rd form of the actual verb. This form is inserted just before the actual verb and, contrary to the continuous aspect where it is followed by 4th form of verb, changes the voice of the sentence to passive.

Here are a couple of examples:

  1. I am writing an essay.
  2. An essay is being written by me.

The first sentence is in present continuous. We have added the underlined form of be, i.e., being, to the second sentence and changed the verb form to 3rd.

  1. Let us do it.
  2. Let it be done by us.

Same as above, we have added be to the second sentence and the form of verb changed to 3rd to change the voice.


Now, let us see how to construct sentences using the ESET Principles and their explanations.

Present Perfect

Sara wants to express that she just finished her conversation with her father. Here is what she needs to do:

  1. Use present tense, which means the prime verb will have 1st form. (Principle No. 1 & 2)
  2. Use a form of have as a prime verb since it gives the meaning of completion. (Explanation No. 2)
  3. Use have itself because it follows first person as such. (Explanation No. 3)
  4. Use 3rd form of the actual verb as have must be followed by this form. (Explanation No. 2)

So, the expression should be:

I have talked to father.

Future Continuous

I want to communicate that Ibrahim will be busy writing an email at a certain time in future. I will:

  1. Use future tense, which means the prime verb will be will. (Principle No. 1 & 2)
  2. Use a form of be after prime verb as it gives the meaning of continuity. (Explanation No. 2 )
  3. Use be itself after prime verb because will is always followed by 1st form of verb. (Explanation No. 2)
  4. Use 4th form of the actual verb after be as the voice of this sentence is active. (Explanation No. 2)

So, the sentence should be:

Ibrahim will be writing an email.

Past Perfect Continuous

Saleh and Sarah want to say that they lived in London continuously for some time but are not there any more. They will:

  1. Use past tense, which means the prime verb will have 2nd form. (Principle No. 1 & 2)
  2. Use appropriate forms of both have and be to show continuity and completion. (Explanation No. 2)
  3. Use had, i.e., 2nd form of have, as the prime verb because the stay has not ended and the expression is about past. (Principle No. 2 & Explanation No. 2)
  4. Use been after had to imply continuity because have and its forms must be followed by a 3rd form of verb or auxiliary verb. (Explanation No. 2)
  5. Use 4th form of the actual verb after been as the voice of the sentence is active.  (Explanation No. 2)

So, the expression will be:

We have been living in London.

Use of Can in Passive Voice

I want to show the possibility of an honor for you in the past while taking you, the subject, for the object of the expression (passive voice). I will:

  1. Use the past tense, which means the prime verb will have a 2nd form. (Principle No. 1 & 2)
  2. Use a could, i.e., a form of can to show the possibility. (Principle No. 2 & Explanation No. 2)
  3. Use be after can, followed by the 3rd form of the actual verb as the sentence is passive(Principle No. 3 & Explanation No. 2 & 6)

Thus, the sentence should be:

You could be given the honor.


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