Past Indifinite: He did the work.
Past Perfect: He had done the work.
তেমনই,
Past Perfect: No sooner had I arrived at the station than the train came.
Past Indifinite: No sooner did I arrive at the station than the train came.
মুলত NO SOONER HAD দ্বারা Past Perfect আর NO SOONER DID দ্বারা Past Indifinite বোঝায়। ব্যপারটা এছাড়া আর কিছুই না।