The intrusive –n– present in some variants functions as a consonantal glide between the unstressed vowel and the following consonant /g/ /dʒ/ or /d/. This phenomenon is present in Old and Middle French but these forms do not persist, while these forms tend to have been adopted in Middle English and continue to be used. E.J. Dobson Eng. Pronunc. 1500-1700 (ed.2,1968) II. §438 discusses the development further but the addition of the –n– remains largely unexplained.