Masculine vs Feminine Forms

Question 1

How do adjectives ending ‘-or’ or ‘-ês’ change in the feminine?

Answer 1

Add an ‘a’

trabalhador –> trabalhadora
inglês –> inglesa (loses circumflex)

Question 2

How do adjectives ending ‘u’ change in the feminine?

Answer 2

Add an ‘a’
cru –> crua

Unless an e precedes the u, in which case the suffix is ‘-eia’
europeu –> europeia

Question 3

how does ‘-ão’ (generally) change in the feminine?

Answer 3

Remove the ‘o’ (-ã)
cristão –> cristã