Derailleur gears operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. For more information about the choice of particular gear ratios and sprocket sizes, see Bicycle gearing. "Derailleur" is a French word, spelled "dérailleur" in French, derived from the derailment of a train from its tracks. Its first recorded use was 1930. At least one notable bicycle industry author has attempted to promote the anglicized spelling of "derailer". As of 2013, however, neither Merriam-Webster nor the Oxford English Dictionary has an entry for "derailer". Various derailleur systems were
Word sort level, regardless of the students' age and grade. Once the appropriate spelling instructional level is established - be it alphabetic, within-word pattern, or syllable juncture - instruction can be adapted by focusing on fewer words at a time, teaching spelling patterns in an explicit manner, and providing for copious amounts of practice and review. Word sort A word sort is a developmental word study activity espoused by the "Words Their Way" curriculum as written by Donald R. Bear, Marcia Invernizzi, Shane Templeton, and Francine Johnston. The activity focuses students' attention on critical features of words, namely sound, pattern, and meaning.