... preposition to is used as an ordinary preposition with verbs of communication such as listen, speak, relate (as in telling someone something), appeal (meaning 'pleading', not as in 'be ... building. We're adding a porch onto the house. In "We're adding on a wing at the back of the building" on is really part of the verb, while in "We're adding a porch ... research and analyze some errors about prepositions of direction, I carried out the survey questionnaire among non-major students in my university. They are second year students and they have...