When a direct speech is transferred into indirect one, the tenses in subordinate clause are subjected to a shift. This shift is performed according to the following rules:
All present tenses are replaced by the correspondent past tenses.
His mother said that he was still sleeping.
Его мать сказала, что он еще спит.He told me that he hadn't spoken to her about it yet.
Он сказал мне, что он не разговаривал с ней об этом.All future tenses are replaced by the correspondent future tenses in the past (shall -> should, will -> would).
He said that he would give me this money.
Он сказал, что он даст мне эти деньги.They informed that they would have finished this program by the end of April.
Им сообщили, что они закончат программу к концу апреля.She promised that she would be waiting for me at the entrance of the metro-station at six o'clock.
Она обещала, что она будет ждать меня у входа в метро в шесть часов.The Past indefinite is replaced by the Past Perfect.
He remembered that he hadn't put the document into the safe before he had left.
Он вспомнил, что не положил документы в сейф, до того, как ушел.The Past Continuous is replaced by the Past Perfect Continuous.
He said that at this time yesterday it had been snowing hard.
Он сказал, что вчера в это время был сильный снегопад.Some pronouns and adverbs can be replaced to:
now -> than, (at) that time
today -> (on) that day
yesterday -> the day before
tomorrow -> the next day
in a few days -> a few days later
a few days ago -> a few days before
ago -> beforeOne should bear in mind that universal truths do not obey the sequence of tenses.
The teacher said that the sun rises in the East.
Учитель сказал, что солнце встает на востоке.