Spelling rules, Present Simple & Present Continuous

For a 3rd person singular in Present Simple:

work-works: add -s.
study-studies: consonant+y - remove y and add -ies
finsh-finishes: sh, s, ch, x: add -es
go-goes; do-does; have-has


For the -ing form:

cook-cooking
study-studying
live-living
run-running