let rnd = System.Random()

let vowels = "aeiou"
let consonants = set ['a'..'z'] - set vowels

let from xs = xs |> Seq.nth (rnd.Next(Seq.length xs))

let vowel () = from vowels |> string
let consonant () = from consonants |> string
let cv () = consonant() + vowel()
let cvc () = cv() + consonant()
let syllable () = (from [vowel; cv; cvc])()

let pseudoword() = String.concat "" [for x in 0..rnd.Next(1,3) -> syllable ()]

pseudoword()