Question

The passenger said to the coolie, "When will the train
arrive?"​

Answer 1

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The passenger asked the coolie when the train would arrive.

Explanation ↴

There are some major rules that we should keep in mind when converting questions in direct speech into indirect speech. In indirect speech, questions starting with who, whose, whom, when, how, where and what the wh-word would be the subject or the object of the reported clause and the 'said to' is replaced by words such as 'asked' or 'inquired'. We do not use a conjunction to introduce the reported speech if the question begins with a wh-word.