Change the following statement into indirect speech.
He said, “Let us go for the morning walk.”
a. He proposed us to go for the morning walk.
b. He ordered us to go for the morning walk.
c. He proposed that they should go for the morning walk.
d. He ordered that they should go for the morning walk.

Hint: Read the given sentence and understand what it conveys. Now, try to convey the same to a third person without quoting the sentence directly. Go through the options and choose the one which matches or is closest to the sentence you framed. Identify the grammatically correct and the most contextually sound option.

Complete answer: In grammar, there are two types of speech that are
recognised - direct and indirect.
In direct speech, the sentence is written exactly as the person said it. However, in indirect
speech, a third person repeats the sentence that was originally said, so there are many
changes in the sentence. For converting from direct speech to indirect speech, the tense has to be changed from present to past. So, to change the speech in this specific sentence, we must change it to simple past tense. As it is a question, in indirect speech, the word order goes back to normal, i.e. the subject comes before the verb. There is also a conditional verb which will be converted into the simple past tense.

Now we know what we are looking for from the options. Let’s look at the given options:
a. He proposed us to go for the morning walk. - This sentence has not changed the
direct object pronoun in the sentence. This makes the sentence grammatically incorrect.
This is not the required answer. So, this is an incorrect option.
b. He ordered us to go for the morning walk. - This sentence has not changed the
direct object pronoun in the sentence and it does not use the correct verb. This makes the sentence grammatically incorrect.
This is not the required answer. So, this is an incorrect option.
c. He proposed that they should go for the morning walk. - This sentence is the correct construction of indirect speech. This is the required answer. So, this is the correct option.
d. He ordered that they should go for the morning walk. - This sentence has not changed the direct object pronoun in the sentence. This makes the sentence grammatically incorrect. This is not the required answer. So, this is an incorrect option.
Therefore, option c is correct.

Note: Simple present tense sometimes gets converted into simple past tense in indirect speech, as it is a reported form of speech. It is not the exact quote someone said.