What is the difference between demek and söylemek? Hello, Demek and söylemek may be used interchangeably most of the time. Ne dedi? - What did he say? Ne söyledi? - what did he say? But we cannot use these two interchangeably in reported speech: Geleceğini söyledi - He told () that he would come. We never say "geleceğini dedi". Instead we use it as: Geleceğim dedi. We never say "geleceğim söyledi"" Instead we use it as geleceğini söyledi i.e. He told that he would come. In reported speeches we use the verb "söylemek" instead of "demek". If we are giving info on what someone said to a third party, we use reported speech (as called in English) . A. He said, "I will come"" or B. He said that he would come. For A we would say - "Geleceğim" dedi in the second case (B) we would say Geleceğini söyledi. I hope this helps.