Complex sentence: The esh is a letter: (upper-case), (lower-case),, borrowed from the same forms of the Greek letter Sigma, by Isaac Pitman in his 1847 Phonotypic Alphabet to represent the voiceless postalveolar fricative.
Split into simpler sentences: The esh is a letter: (upper-case), (lower-case). It was used by Isaac Pitman in his 1847 Phonotypic Alphabet to represent the voiceless postalveolar fricative.