Converting direct to reported speech: who-question

Question

The teacher asked Marga, "Who helped you with your work?"

Would "The teacher asked Marga who had helped her with her work." be an acceptable conversion to reported speech?

Answer 1

The teacher asked Marga, "Who helped you with your work?"

The teacher asked Marga who had helped her with her work.

Because the original question was a subject question and there was no subject auxiliary inversion, the reported speech doesn't require any change of word order there. The reported version uses the past perfect, to reflect the anteriority of the help in relation to the question. The pronouns have all been adjusted accordingly. The punctuation has been adjusted accordingly. So the reported speech sentence in the Original Poster's question is perfectly well-formed and correct.