In English we can use several constructions to agree with a statement. Here, we are using "So + Auxiliary + Subject" (So do I.) to agree with a positive phrase, and "Nor / Neither + Auxiliary + Subject" (Neither do I.) to agree with a negative. In Spanish the equivalent is "Yo también" and "Yo tampoco". Look at the following examples

Match the items on the left to the items on the right.
Une un elemento de la izquierda con otro de la derecha.