Language/French/Grammar/Use-of-l'on

Use of l'on

l'on is sometimes used in French for on when it follows a word ending in a vowel (like et, ou, qui, que, si, etc). This is a feature of written, rather than spoken, French:

• Comment savoir si l'on ne demande pas?

How can you know if you don't ask?

• Il faut savoir choisir l'homme avec qui l'on s'engage pour la vie

You have to be careful choosing the man to whom you will commit your life

The use of l' is not obligatory, however.