What's it "so do I" rather than "I do so?"

Rebecca

"So do I" has a meaning similar to "me too!" Basically, you can use it to express agreement with something someone else has said, especially when it refers to an action or preference. Depending on whether "to do" or "to be" verb form should be used, you can also say "so am I." Note that you can replace "I" with other pronouns like he, she, they, and you. Ex: A: I love to go swimming. B: So do I! Ex: A: I'm a huge fan of basketball. B: So am I.