What does "that" mean here? Is it an emphasis?
Native speaker’s answer
Rebecca
Yes, the speaker has used "that" to emphasize the level of negativity. In this context, "that" can be understood as meaning something like "so" or "to such a degree/extent." Thus, we can understand "it's hard to listen when somebody's that negative" to mean "it's hard to listen when somebody's negative to such an extent." Ex: It's hard to compete when someone's that talented. (Talented to such an extent) Ex: Your haircut's not that bad. I think it's cute. (Your haircut is not so bad)