Previously I asked someone and they confirmed that the usage of "un/uno" is aligned with "il/lo", both use the O version before a noun that starts with S + a consonant or Z or PS.
However some told me that there are cases where you use il for a singular noun but gli for its plural form. I have forgot the details.
Are all nouns that use il as their singular article use i as their plural article? If not, is there a word that you would say il something and at the same time gli somethings?