Is it ok to omit "is" here and just say "I believed you were trying to say 'thank you.'"?
Native speaker’s answer
Rebecca
If the sentence is simply "I believe you were trying to say "thank you"" would be fine grammatically. However, because of "so what" in this clip we cannot omit "is". Also omitting "so what" loses the nuance that he is correcting her. Ex: I believe you were saying sorry. Ex: So what you were saying is sorry.