Tense Rules

Rule1:-

If a sentence starts with past tense, it can only end with past tense. If a sentence starts with present tense, it can end with present, past or future tense; but if a sentence starts with future tense, it can only end with simple present tense.

Starting/ Ending of Sentences

♦ Past Tense ⇒ Past Tense

- He said he was going to the market. (correct) [usage of ‘was going’ as ‘said’ is used in starting]

♦ Present Tense ⇒ Present, Past or Future Tense

- I know you will do it. (correct) [can end in any tense]

♦ Future Tense ⇒ Simple Present Tense.

- We will not go there if it rains. (correct) [usage of ‘simple present tense (it rains)’ as sentence starts with future tense]

Rule2:-

When two of the future course of actions are stated then simple present tense is used with the clause beginning with if/ till/ until/ unless/ when/before/ after/ as soon as/ as long as/ in case / even if etc. (time indicator words)

- We will go there even if it rains. (correct) [two actions of future- a) will go | b) rain, time indicator word- even if]

Rule3:-

The universal truths are always expressed in simple present tense. Even if a sentence starts with past tense & then also the universal truth must be in simple present tense.

- Anita said that the earth revolves around the sun. (correct) [starts with past tense, ends in simple present tense.]

If a sentence starts with the above phrases/words then it should be used in present continuous form.