Lon or On Euphony in French Pronunciation

On  is the French impersonal subject pronoun, and normally shouldnt be preceded by l neither the direct object definite article In Old French,  on  was the subject case for the noun   homme, so  lon  at this time meant  les hommes. When the subject case disappeared in French,  on  stuck around as a pronoun, and retained the ability to take the definite article.  Lon  is much more common in written French than in spoken, because it is a formal, elegant construction, and writing tends to be more formal than speech. Today, this l is simply considered a  euphonic  consonant and is used in the following situations: 1.  After certain monosyllabic words that end in a vowel sound, like  et,  ou,  oà ¹,  qui,quoi, and  si, to avoid a  hiatus. Sais-tu si lon a demandà ©Ã‚  ?   (avoid  si on)   Do you know if someone asked?...et lon a dit la verità ©.               (avoid et on)   ...and they told the truth. 2.  After que, lorsque, and puisque, to avoid the contraction  quon  (sounds like con), especially if the next word begins with the sound con. Lorsque lon est arrivà ©... (avoid  lorsquon)   When we arrived...Il faut que lon comprenne. (avoid  quoncomprenne)   Its necessary for everyone to understand. 3.  At the beginning of a sentence or clause. This usage of  lon  is not a question of euphony, but rather a holdover from  là ©poque classique  and is thus very formal. Lon ne sait jamais.   One never knows.   Ã‚  Lorsque je suis arrivà ©, lon ma dit bonjour.   When I arrived, everyone said hello. Note: For the purposes of euphony,  on  is used instead of  lon After  dont  (le livre dont on a parlà ©)In front of words that begin with  l  (je sais oà ¹ on lit)