adjectives of nationality
Change the masculine singular adjective of nationality to agree with the named gender and number. Remember the rules, if m/s ends in -o, change -o to -a for f/s; add -s to both for plural. If m/s ends in -e, f/s stays the same; add -s for both plural. If m/s ends in -l, -n or -s, add -a for f/s; add -es for m/p and -s to the f/s. Exception is vietnamita which is m/f/s form; apply the vowel rule for plural.