" So ” or “ too ” in spoken English are used in positive sentences to show agreement.
Structure :
1. POSITIVE SENTENCE, TOO
2. SO + AUXILIARY + SUBJECT [ Auxiliary (do/ does/ have/ should/…]

Example :
Person A : I love football.
Person B : I love football, too. / So do I.

Person A : Ram can swim.
Person B : I can swim, too. / So can I.

Person A : Ram and Sohan have done their tasks.
Person B : I have done my tasks, too. / So have I.