Is "Ex adversitas felicitas" correct grammar and does it mean that from adversity comes happiness?
“Ex adversitate felicitas” is the correct Latin wording for this sentence whose meaning is just “From adversity comes happiness”.
Please note that : EX (preposition which takes the ablative case) means “from”; ADVERSITATE (ablative singular of the noun ADVERSITAS, 3rd declension) means “adversity”; FELICITAS (subject in the nominative singular, 3rd declension) means “happiness”.
As for the English verb “comes”, it is implied in Latin.
To sum up, “Ex adversitas felicitas" is incorrect because “adversitas” is a nominative case which is wrong here, as it must be in the ablative case, i.e. “adversitate”, for it depends on the preposition “ex” which must be followed by the ablative case.
Hope this is clear enough.