So do I

So do I

So am I, so do I

• We use so with be and with modal and auxiliary verbs to mean ‘in the same way’, ‘as well’ or ‘too’. We use it in order to avoid repeating a verb, especially in short responses with pronoun subjects. When we use so in this way, we invert the verb and subject, and we do not repeat the main verb

• Ex. Geoff is a very good long-distance runner and so [V]is [S]his wife.

Neither do I / I don't either

• I don’t think she’ll be coming to the party.
• Neither do I. (or I don’t either.)