yes Cody, they can! my goofy brother grew taller from about 17 till 22. although this is a bit unusual, it is not exactly rare. i am 5'7" and he's 6'2" or so. of course, i'm "cool" and he's a jerk...so it all balances out! lol. stay safe Cody, and celebrate life...;-)
The answer is yes. You can find out whether a person is finished growing by xray-ing one of the "long bones". We have growth "plates" on those bones and until those growth areas have fully hardened one can continue to grow. Usually growth is limited after age18, but some residual growth may occur.