Look at these two examples:
J'habite à Londres.
I live in London.
Notice that the pronoun je ('I' in English) becomes j' when used in front of verbs beginning with a vowel (a, e, i, o, or u) or a silent 'h'.
This contraction changes the pronunciation and is called elision.
Learn more about these related French grammar topics
Examples and resources
Q&A

Laura
Kwiziq language super star
22/07/16
I find that hard to believe, but the grammar is perfect. :-)
Marathuduwa gamage
Kwiziq community member
16 November 2017
2 replies
How to change je suis to j
Aurélie
Kwiziq language super star
17 November 2017
17/11/17
"suis" doesn't start with a vowel, so you won't need to contract "je" here : it will always be "je suis".
However, you will use j' with verbs like : avoir, aimer, habiter, entendre, écouter, oublier, inventer, utiliser ...
I hope that's helpful!
À bientôt !
Lizbety
Kwiziq community member
8 October 2018
8/10/18