in changing direct speech to indirect is it compulsory to change verb in 3 Rd form of verb

The changes in the verb from direct to indirect speech depend on the tense used in the principal verb of the given sentence. It does not necessarily have to change to the third from of the verb in all cases. Many other rules also come into play. they have been explained below:

- Present Tenses in the Direct Speech are changed into Past Tense if principal verb is in the past tense.
- Do not change tense of reported Speech in Indirect Speech sentence if in direct speech you find say/says or will say. Or The reporting verb is in a present tense. Or the words within the quotation marks talk of a universal truth or habitual action.

The other changes in tense are given below:
Present Continuous Changes To Past Continuous
Present Perfect Changes To Past Perfect
Present Perfect Continuous Changes To Past Perfect Continuous
Simple Past Changes To Past Perfect
Future Changes To Present Conditional
Future Continuous Changes To Conditional Continuous
There is no change in past perfect and past perfect continuous tenses.