A man has been recorded spending more than three hours to pronounce what is supposedly the longest word in the English language. 'Methionylthreonylthreonylglutaminylarginyl...isoleucine' is the chemical name of 'titin' (also known as 'connectin') - the largest known protein. It has 189,819 letters. However, in the past it has been disputed whether or not it is a real word - proteins are named after the chemicals involved in making them.