Shall I? Shall I? When you just don't know what to do, it may feel as if asking that question twice will somehow help you decide. The 17th century saw the use of the phrase "stand shall I, shall I" to describe vacillation or indecision. By that century's end, the phrase had been altered to "shill I, shall I," most likely because people just liked the vowel alteration (that's the same process that gave us dillydally and wishy-washy). Soon after, the adverbial shilly-shally made the jump from slang to literature and writers began applying it as an adjective, a noun, and a verb as well.