In English, there is no difference. Adjectives do not change for gender or number; neither do articles. Using your example, we would say:

* the incredible man
* the incredible woman
* the incredible men
* the incredible women

To review: Adjectives are easy to translate, because they do not change in English. Spanish "el/la/los/las/lo" are translated "the" in English. Spanish "un/una" are translated "a" (before a consonant: "a dog") or "an" (before a vowel: "an apple"). Spanish "unos/unas" don't have an exact translation. If you translate them, use "some." For example:

* Hay [unos] elefantes en la casa.
* There are [some] elephants in the house.

Good luck,
George