Tell and say are present tense verbs. Told and said are past tense verbs. You would say, for example, "She tells a story" to say that she's saying it right at that moment. You would say "She told a story," to say that she told it in the past. For said/said, for example, you would say "She said so." to say that it happened in the past. To say that it is happening, you would use "says". Hope that helps.

the difference between tell and say ,is the verb tell used when you say something new (story , information,secret) and the verb say is not about something new . So, we say for examble :I will tell you a secret and , hey Sami say something

Use "tell" when you want to relate specific information or give someone instruction, tell+somebody+phrase. Use "say" to report someone's speech, either directly or indirectly, say+(to someone)+phrase.