Learn about the right order of cases.

   Nouns-             The teacher teaches to the students the sentence - who teaches to whom what - dat, akk

   Pronouns-           He teaches it to them - who teaches what to whom -                       akk, dat

    Noun/ pronoun -     He teaches to them the sentence -                                  pronoun, noun

    Noun/ pronoun       He teaches it to the studentents                                    pronoun, noun