linguisticsgirl.com: ... In my mind, grammatical *form**(what a word looks like) is clearly separate from grammatical function (what a word does). From ODO: 2.1. Any of the ways in which a word may be spelled, pronounced, or inflected 4.2. [count noun] A set order of words; a formula:
When Michael J. Fox played 'Johnny B. Goode' as Marty McFly in 'Back to the Future' in 1985, he was just aping Chuck Berry's classic fretwork for the camera. (Along with some Jimi Hendrix, Eddie Van Halen and Pete Townsend guitar moves thrown in for good measure.) Today, Fox can really play the song.
For other uses, including uses related to the franchise, see Back to the Future (disambiguation). Back to the Future is a 1985 American science-fiction adventure comedy film directed by Robert Zemeckis and written by Zemeckis and Bob Gale. It stars Michael J. Fox as teenager Marty McFly, who is sent back in time to 1955, where he meets his future parents in high school and accidentally becomes his mother's romantic interest.