Guido io was given as the translation of I drive.
Why not just Guido or Io guido or are they all correct?
All of them are correct, but I think that it is related to the context; "Guido io" can be seen as an imperative verb, for example two friend go back to the car and one says " Guido io" meaning "I drive and I don't want to negotiate with you". "Io guido" it's the present tense "I drive" usually followed by somenthing else in the sentence for example "Io guido l'auto" can be translated "I drive the car". About "Guido" alone I will use it only in a context of a question, "Cosa stai facendo?" re "Guido" translated as " What are you doing?" re " I drive" but with the meaning "I drive...don't bore me with your question "