Formula of Past Indefinite Tense is an important topic because to learn any tense as whole, you must learn how to derive/make formula. It helps the learners to create concepts for this tense formula. Let us learn how we can derive the formula of past indefinite tense.
Basic Parts of Past Indefinite Tense
There are three basic and main parts of speech for this tense: subject (s), verb (v), and object (o).
S + V + O
Note: We will derive or make formula from the title of past indefinite tense.
Target: As past indefinite tense has three main parts subject, verb, and object. The thing we will decide is the form verb whether it will be 1st or 2nd which is main concern.
Step 1 to Derive Formula Of Past Indefinite Tense
Indefinite: Indefinite means the first or second form of the verb. But we want can’t use both of forms after subject. We must have to choose one of them. Indefinite does not decide whether the 1st form will be consider or the 2nd.
Step 2 to Derive Formula Of Past Indefinite Tense
Present: Past shows the second form of verb (2nd V) because when we learn three forms of the verbs, the first form is called ‘present’, second is ‘past’ and third is ‘past participle’. So, here we are concerned about past ,therefore, second form will be used. Hence, the formula will be:
S + 2nd V + O

Formula Of Past Indefinite Tense for Negative Sentences
Its very easy to derive the formula for negative sentences after learning general formula. So, add ‘not’ after helping verb. Furthermore, no helping verb in general formula of this tense. Therefore, we use additional helping verbs ‘did’. Formula Of Past Indefinite Tense for Interrogative Sentences
S + did+ not + 1V + O
Formula Of Past Indefinite Tense for Interrogative Sentences
According to the rule, write helping verb (did) at the start ending with question mark.
Did + S + 1V + O ?
Formula Of Past Indefinite Tense for Interro-negative Sentences
Simply, pick the helping verb (did) from negative sentence and place at the start of the sentence ending with question mark/sign of interrogation.
Did + S + not + 1V + O?
To learn present indefinite tense completely, click here.