Some 3rd group verbs, such as ouvrir (to open), end as follows:

ouvrir	to open
j'ouvre	I open
tu ouvres	you open
il ouvre	he opens
nous ouvrons	we open
vous ouvrez	you open
ils ouvrent	they open

NB: "ouvre", "ouvres" and "ouvrent" should be pronounced the same way. Do not pronounce final "s".

Other verbs like ouvrir:

verb
offrir (to offer)	j'offre, tu offres, il offre, nous offrons, vous offrez, ils offrent
souffrir  (to suffer)	je souffre, tu souffres, il souffre, nous souffrons, vous souffrez, ils souffrent

and also all verbs based on ouvrir: couvrir (to cover), découvrir (to discover), recouvrir (to cover), entrouvrir (to open a little), rentrouvrir (to open a little again), rouvrir (to open again).