Some 3rd group verbs, based on dire (to say), are irregular and end as follows:

dire	to say
je dis	I say
tu dis	you say
il dit	he says
nous disons	we say
vous dites (irreg.)	you say
ils disent	they say

NB: "dis" and "dit" should be pronounced the same way. Do not pronounce final "s" or "t".

Other verbs based on dire:

contredire (to contradict), dédire (to retract), interdire (to forbid or to prohibit), médire (to malign), prédire (to predict), redire (to say again),