former
In Italian, 'ex' is used in front of a noun to indicate someone's former role. For example, 'ex presidente' means 'former president'. Note that 'ex' stays invariant regardless of the gender and number of the noun it precedes.
He was God, now he is king.
This sentence demonstrates one possible usage of 'ex' in Italian. 'Ex' is a Latin preposition which has been incorporated into Italian, and it means 'formerly'. In this case, 'ex' is used to create a contrast between past and present.
My ex was a good man.
This sentence shows how 'ex' can be used as an adjective in Italian to denote something or someone from the past. In this case, 'ex' is used to refer to a former partner or spouse.
The former president is always very respected.
This sentence demonstrates the use of 'ex' to indicate a former role or position someone held. Here, it is used to refer to a person who was previously a president.