Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
plan (n., v.)
To make plans for the future, to do future planning, and to have future plans all have been criticized as redundant, as have advance[d] planning and to plan in advance or to plan ahead. To plan out extends the idea in a slightly different sense. All these locutions are Standard when restricted to Conversational, Semiformal, and Informal levels. The more Formal the prose, however, the more likely editors and readers are to be sensitive to possible redundancies.
The verb plan combines frequently with on and to, forming Standard idioms we use constantly: Plan on my being there by eight. Please plan to stay for dinner. We’ll plan on pizza and beer after the game.
