Yesterday, Chuck [was] (be) very busy. He left work at 8 pm. Today, I [haven't talked] (not/talk) to him yet.

A frase correta seria: "Yesterday, Chuck was very busy. He left work at 8 pm. Today, I haven't talked to him yet." A primeira frase está no passado simples, com o verbo "was" no passado do verbo "to be". Já a segunda frase está no presente perfeito negativo, com o verbo "haven't talked" no presente perfeito do verbo "to talk" e a palavra "not" para negar a ação.